Mask fabrication supporting method, mask blank providing method, and mask blank dealing system

ABSTRACT

A mask blank is provided by forming a plurality of films, including at least a thin film to be a transfer pattern, on a board. At the time of patterning a resist film of the mask blank according to pattern data, film information to check with a pattern is obtained for each of a plurality of the films.

TECHNICAL FIELD

This invention relates to a mask blank for semiconductor manufactureand, in particular, relates to acquisition and management of mask blankquality information and the manufacture of a mask blank and a mask.

BACKGROUND ART

As a conventional technique relevant to this invention, JapaneseUnexamined Patent Application Publication (JP-A) No. 2003-149793 iscited. According to the technique described in this publication, it isdescribed that a blank maker classifies blanks by defect ranks accordingto inspection results and supplies the blanks to a mask maker whileattaching defect information.

On the other hand, Japanese Unexamined Patent Application Publication(JP-A) No. 2003-248299 discloses a technique for accurately locating adefect position on a photomask substrate.

In these conventional techniques, although the defect informationprovided along with the mask blank shows the relative positionrelationship between defects existing on the mask blank surface, thereis provided no reference for correspondence between the mask blank andthe position information of the defect information. Therefore, even ifthere is the defect information, it is not possible to accurately locatewhere the defects exist on the actual mask blank and, hence, patternfailure occurs in the writing/development process. Further, there is nodefinite guarantee in terms of providing agreement between a directionof the mask blank placed in a receiving case and a direction of thedefect information. Therefore, the actual mask blank and the defectinformation are deviated by 90 degrees, 180 degrees, or 270 degrees sothat the pattern failure occurs in the writing/development process. Thisis because, in the manufacturing process, after taking out a substrateplaced in a container such as a distribution case, a cassette, or areceiving case and applying predetermined treatment thereto, whenplacing it again in another container, there is no means for confirmingthat the direction of the placed substrate is the same in the formercontainer and the latter container.

Conventionally, there has been no particular disadvantage with suchdefect information in fabrication of masks by a mask maker. This isbecause, in the case of a conventional exposure light source such asi-line (wavelength 365 nm) or KrF (wavelength 248 nm), the allowabledefect levels, i.e. the allowable ranges of the size and number ofdefects, are not so narrow.

However, following higher integration of semiconductor devices, patternsare complicated and the line widths thereof are narrowed. In order tocope with it, the wavelengths of exposure light sources are shortenedand ArF (wavelength 193 nm), F2 (157 nm), and so on are examined aslight sources, and as a result, it is expected that the allowable defectlevels for masks will be stricter than before.

Further, because of the complication and miniaturization of patterns,the time and cost required for manufacturing a mask by writing a patternwith a writing apparatus have been rapidly increasing. Therefore, theneed has been increasing for suppressing pattern defects caused by maskblanks. As such pattern defects, there are, for example, defects calledparticles and pinholes.

On the other hand, as mask blanks adapted for the miniaturization ofpatterns, the demand for phase shift mask blanks has been increasing. Ina halftone phase shift mask blank being one type of the phase shift maskblanks, there are formed a halftone film, a light shielding film, andfurther a resist film if necessary. The halftone film has a lightshielding function and a phase shift function and thus has a roledifferent from that of the light shielding film.

In order to achieve improvement in yield of the mask manufacturingprocess, simplification of the process, cost reduction, and so on, it isnecessary to obtain defect information of each of the films forming themask blank.

Patent Document 1:

-   Japanese Unexamined Patent Application Publication (JP-A) No.    2003-149793    Patent Document 2:-   Japanese Unexamined Patent Application Publication (JP-A) No.    2003-248299

DISCLOSURE OF THE INVENTION Problem to be Solved by the Invention

However, according to the conventional techniques, there is no need foracquiring defect information of each of the films and only the resultsof inspection of the mask blank in the final shipping form are providedas described above. Therefore, a blank maker does not manage defectinformation per substrate in the mask blank manufacturing process andthus cannot provide defect information of each of films forming a maskblank to a mask maker.

Consequently, the mask maker cannot suppress occurrence of patternfailure in the writing/development process caused by defects of maskblanks.

Further, although the pattern failure is normally corrected in a patterncorrection process by the use of a FIB (focused ion beam), a laser, orthe like, since the pattern complication/miniaturization has advanced,the case has appeared where the correction is disabled. In such a case,a mask should be manufactured again from the beginning.

This invention has been made under these circumstances and has an objectto provide a mask fabrication supporting method that can suppresspattern failure caused by a mask blank when a mask is fabricated fromthe mask blank. Another object is to provide a mask blank providingmethod and a mask blank manufacturing method where film information isadded so as to enable suppression of pattern failure due to a mask blankwhen a mask is fabricated from the mask blank. Further, another objectis to provide a transfer mask manufacturing method that can improve themanufacturing yield and suppress the manufacturing cost by collating apattern, to be formed, with film information.

Means for Solving the Problem

For accomplishing the foregoing objects, this invention provides thefollowing techniques.

(1) To provide a mask fabrication supporting method of providing filminformation of a plurality of films forming a mask blank to a mask makerand suppressing pattern formation failure when fabricating a transfermask from the mask blank by patterning the film, a mask blank providingmethod, a mask blank manufacturing method, and a method of manufacturinga transfer mask by the use of the mask blank.

Specifically, in the mask blank manufacturing process, a managementnumber is assigned to a substrate and film information of a plurality offilms are collated based on the management number, or film informationof a plurality of films are collated based on surface form information(convex portion or concave portion) formed at the same position in therespective film information of the plurality of films, so that positioninformation between the plurality of film information is guaranteed tothereby prevent pattern failure in the mask fabrication.

Another aspect of this invention is as follows.

In the mask blank manufacturing process, identification of individualsis carried out by utilizing means such as assigning management numbersto respective substrates or mask blanks offered for production.

Then, a plurality of films are stacked in order on the substrate andfilm information about the films is acquired.

The film information is state information of a film including surfaceinformation of the film, surface form information, for example, a convexshape, a concave shape, or their combination on the film surface,optical property information, or the like and is information correlatedwith position information of the film surface. The optical propertiesreferred to herein include transmittance, reflectance, absorptivity,phase difference, and so on.

The film information acquired about the plurality of respective filmsstacked on the substrate can be individual-identified based on themanagement number or the like so that the information is mutuallycollated. Therefore, the relationship between the mask blank individualand the acquired plurality of film information is guaranteed and therelationship between the plurality of film information can beguaranteed, and further, the position in the mask blank indicated byposition information included in the plurality of film information isguaranteed.

Substrate information about the substrate may be acquired herein.

The substrate information is state information of a substrate includingsurface information of the substrate, surface form information, forexample, a convex shape, a concave shape, or their combination on thesubstrate surface, optical property information, or the like and isinformation correlated with position information of the substratesurface. The optical properties referred to herein includetransmittance, reflectance, absorptivity, phase difference, and so on.

By forming a film on the substrate and acquiring substrate informationabout the substrate and film information about the film, since thesubstrate information and the film information can beindividual-identified based on the management number or the like andcollated with each other, the relationship between the mask blankindividual and the acquired substrate information and film informationis guaranteed and the relationship between the substrate information andthe film information can be guaranteed, and further, the position in themask blank indicated by position information included in the substrateinformation or the film information is guaranteed.

The management number is not necessarily assigned to the substrate.Since the surface form of a film is formed according to the surface formof a film being an underlayer of the subject film or according to thesurface form of the substrate, by collating form information included inthe plurality of film information or form information included in thefilm information and the substrate information, the relationship betweenthe mask blank individual and the acquired film information or substrateinformation can be guaranteed, the relationship between the plurality offilm information or the relationship between the film information andthe substrate information can be guaranteed, the relationship betweenposition information included in the plurality of film information andthe position in the mask blank is guaranteed, and the relationshipbetween the position information included in the substrate informationor the film information and the position in the mask blank isguaranteed.

In this invention, with respect to a mask blank individual comprising asubstrate and films formed on the substrate, mask blank informationcomposed of substrate information and film information, or of aplurality of film information is acquired. Further, position informationincluded in the mask blank information guarantees the position in themask blank. That is, the mask blank information in this invention ischaracterized by being three-dimensional information of the mask blankand being acquired so as to be recognizable as internal information ofthe mask blank, i.e. mask blank in-body information.

Since the information not only about the surface of the mask blank, butalso about the inside of the mask blank body can be grasped in advance,it is possible to prevent fabrication of a defective transfer mask inthe mask fabrication.

This invention includes a structure in which a reference point ofposition of the position information included in the mask blankinformation and a reference point of position of the mask blank arecorrelated with each other to thereby acquire information. Further, itincludes a structure in which a reference point of position of theposition information included in the substrate information and areference point of position of the substrate are correlated with eachother to thereby acquire information. Further, it includes a structurein which a reference point of position of the position informationincluded in the film information and a reference point of position ofthe substrate or the film are correlated with each other to therebyacquire information.

(2) To provide a mask fabrication supporting method of providing surfaceinformation of a mask blank including surface form information andposition information to a mask maker and correlating this surfaceinformation and the surface form of a mask blank by respectivelyprovided reference points, thereby allowing a mask fabricator to specifya region of pattern formation, a mask blank providing method, a maskblank manufacturing method, and a method of manufacturing a transfermask by the use of the mask blank.

Specifically, when placing a mask blank in a receiving case which isused in the processes of the mask blank manufacture or for providingmask blanks to a mask maker, the directivity of a substrate is managed(aligned in a certain specific direction) according to a reference markprovided on the substrate or over the substrate so that surfaceinformation including surface form information and position informationin the mask blank and the position of the surface form of the mask blankcan be made correspond to each other, thereby preventing pattern failurein the mask fabrication.

Herein, the film information is information obtained by variouslyinspecting a film immediately after formation thereof on the substrate.The film information includes surface form information indicating theposition, size, type, and so on of a defect on a film and compositiondistribution information indicating a composition distribution in thefilm surface including the position and range where a film materialpartially changes in composition, the state after the change incomposition, and so on. Surface information including surface forminformation of an uppermost film serving as the surface after thecompletion of a mask blank is called mask blank surface information.

Another aspect of this invention is as follows.

To provide a mask fabrication supporting method of providing the maskblank information to a mask maker such that the mask blank informationand the mask blank individual relating to this information can becorrelated with each other, thereby allowing a mask fabricator to selecta region where a predetermined mask pattern is to be formed on the maskblank, a mask blank information providing method, a mask blank providingmethod, a mask blank manufacturing method, and a method of manufacturinga transfer mask by the use of the mask blank.

This invention includes a structure in which a reference point ofposition of position information included in the mask blank informationand a reference point of position of the mask blank are correlated witheach other.

This invention includes a structure in which the arrangement anddirectivity of substrates or mask blanks are managed when placing thesubstrates or the mask blanks in a receiving tool which is used in themask blank manufacturing processes and/or for providing mask blanks to amask maker. For example, it includes a mode in which a plurality ofsubstrates or a plurality of mask blanks are placed while being alignedin a certain direction. In this event, the placement may be carried outwhile referring to reference points provided on the substrates, films,or mask blanks.

For example, the mask blank manufacturing processes include a process ofpreparing a substrate, a process of acquiring substrate information(e.g. substrate inspection process), a process of forming a film on thesubstrate, a process of acquiring film information (e.g. film inspectionprocess), a process of placing a mask blank in a receiving tool in orderto provide the mask blank to a mask maker, and so on and, in thesubstrate or mask blank placement operation carried out in theseprocesses, the mode is included in which a plurality of substrates or aplurality of mask blanks are placed while being aligned in the certainpredetermined direction in order to manage the directivity of thesubstrates or the mask blanks.

The receiving tool referred to herein includes, for example, alater-described holder or case. As the reference point referred toherein, use can be made of, for example, an identifiable mark.

As the mark or the reference mark for use in this invention, use can bemade of, for example, a mark, called a notch mark, given to a substrateor a mark, called a film mark, given to a film, which will be describedlater.

When the mask blanks are provided while being placed in the foregoingmanner, since the mask blanks are provided while being aligned in thepredetermined arrangement and the predetermined directivity, a maskfabricator can identify the mask blank individuals and comprehend theposition reference points of the mask banks by referring to or withoutreferring to the reference points.

According to this invention, through the position reference point of themask blank, the surface information and the internal information of themask blank for fabricating a transfer mask therefrom can be graspedbased on the provided mask blank information and, hence, the maskfabricator can select a region where a predetermined mask pattern is tobe formed. That is, since the mask fabricator can comprehend thepresence of a surface defect or an internal defect that will causepattern failure or impede a certain function of a transfer mask beforeforming a predetermined mask pattern, it is possible to improve themanufacturing yield to thereby achieve production of transfer masks withhigh profit rate or production of low-priced transfer masks.

The present invention is preferably used for a mask blank or a transfermask formed with a phase shift film, for example, a halftone film. Forexample, a halftone phase shift mask being one type of phase shift masksis formed with a halftone film and a light shielding film on anoptically transparent substrate. The halftone film has both a lightshielding function of substantially shielding exposure light and a phaseshift function of shifting the phase of the exposure light and thus hasa function of controlling the transmittance and the phase difference tothereby highlight the pattern edge of a pattern transferred to atransfer target. The halftone phase shift mask is formed with thepattern of the halftone film on the optically transparent substrate andcomprises a light transmitting portion formed with no halftone filmpattern and adapted to transmit light with an intensity thatsubstantially contributes to the exposure and a light semitransmittingportion formed with the halftone film pattern and adapted to transmitlight with an intensity that does not substantially contribute to theexposure. Further, the phase of the light having transmitted the lightsemitransmitting portion is in a substantially inverse relationship tothe phase of the light having transmitted the light transmittingportion. Therefore, the lights having passed through the vicinity of aboundary portion between the light semitransmitting portion and thelight transmitting portion and mutually diffracted into the others'regions through the diffraction phenomenon serve to cancel each other tomake substantially zero the light intensity at the boundary portion,thereby improving the contrast at the boundary portion. Accordingly, thequality required for the mask blank formed with the halftone film ishigher as compared with a mask blank formed only with a mere lightshielding film and, further, when applying a patterning process to themask blank to fabricate a transfer mask, it is difficult to reduce thepercent defective.

This invention provides the following techniques.

To provide a mask fabrication supporting method of providing, to a maskmaker, film information for specifying a region to be subjected topattern formation in order to suppress pattern formation failure whenfabricating a transfer mask from a mask blank, formed on a substratewith a plurality of films including at least a thin film which is to bea transfer pattern, by patterning the thin film, the mask fabricationsupporting method characterized in that the film information isinformation obtained from the plurality of films forming the mask blank.

The pattern may have a dense pattern forming region where a relativelydense pattern is formed and a sparse pattern forming region where arelatively sparse pattern is formed.

The film information may include any of the type of a convex portion ora concave portion that will cause a pattern defect, the size of theconvex portion or the concave portion, and position information of theconvex portion or the concave portion.

The position information may be produced on the basis of a notch markformed on the substrate and/or a film mark by the thin film formed atthe peripheral portion on the main surface of the substrate.

Part or all of the mask blank information, the substrate information,and the film information may be provided by the use of a communicationline.

The films may include a phase shift film having a phase shift functionwith respect to exposure light.

Further, this invention provides a mask blank providing method ofproviding the foregoing mask fabrication supporting method along withthe mask blank to a mask maker, the mask blank providing methodcharacterized in that the mask blank is provided while being placed in areceiving case and held by a holder having a holding slot formed forholding the mask blank and the mask blank information is identified bymask blank specifying means indirectly assigned to the mask blank.

The mask blank information may be identified by a slot number assignedto the slot of the holder.

Further, this invention provides a mask blank manufacturing methodcomprising a process of preparing a substrate for a mask blank, a thinfilm forming process of forming a thin film, which is to be a transferpattern, on the substrate, a thin film information acquisition processof acquiring film information of the thin film, a thin film informationrecording process of recording and storing in an information storagemedium the film information of the thin film acquired in the thin filminformation acquisition process, a resist film forming process offorming a resist film on the thin film, a resist film informationacquisition process of acquiring film information of the resist film, aresist film information recording process of recording and storing in aninformation storage medium the film information of the resist filmacquired in the resist film information acquisition process, and a filminformation collation process of collating the film information of thethin film and the film information of the resist film.

Herein, after the process of preparing the substrate for the mask blank,there may be included a substrate information acquisition process ofacquiring substrate information of the substrate. Further, there may beincluded a substrate information recording process of recording andstoring in an information storage medium the substrate informationacquired in the substrate information acquisition process. Further,there may be included a collation process of collating the substrateinformation and the film information.

After preparing the substrate for the mask blank, there may be provideda management number assigning process of assigning a management numberto the substrate for the mask blank, and the film information of thethin film and the film information of the resist film may be collatedbased on the assigned management number. Further, the substrateinformation and the film information may be collated.

The substrate information or the film information may include any of thetype of a convex portion or a concave portion, the size of the convexportion or the concave portion, and position information of the convexportion or the concave portion.

The position information may be produced on the basis of a notch markformed on the substrate and/or a film mark by the thin film formed atthe peripheral portion on the main surface of the substrate.

The substrate information, the film information of the thin film, andthe film information of the resist film may be collated based onspecific forms, for example, convex portions or concave portions,included in the substrate information, the film information of the thinfilm, and the film information of the resist film and formed at the sameposition.

Further, this invention provides a transfer mask manufacturing method ofusing a mask blank formed on a substrate with a film including at leasta thin film which is to be a transfer pattern and patterning the thinfilm according to pattern data to be formed, thereby fabricating atransfer mask, the transfer mask manufacturing method characterized bycollating the mask blank information acquired by the foregoing maskfabrication supporting method and the pattern data and, in order tosuppress pattern formation failure, specifying a region to be subjectedto pattern formation in the mask blank.

The pattern may have a dense pattern forming region where a relativelydense pattern is formed and a sparse pattern forming region where arelatively sparse pattern is formed.

The next invention is also included in this invention. That is, there isprovided a mask fabrication supporting method of providing, to a maskfabricator, mask blank information necessary for specifying a region tobe subjected to pattern formation in order to suppress pattern formationfailure when fabricating a transfer mask from a mask blank, formed on asubstrate with a film including at least a thin film which is to be atransfer pattern, by patterning the thin film, the mask fabricationsupporting method characterized in that the mask blank informationincludes surface form information, a reference point of position of thesurface form in the mask blank provided to the mask fabricator and areference point of position information corresponding to the surfaceform information correspond to each other, and the mask fabricatorreflects the mask blank information on the mask blank through thereference points to comprehend the state of the mask blank, therebyspecifying the region to be subjected to the pattern formation.

A reference mark may be provided on the substrate or over the substrateand the reference point of the position information may be produced soas to have a certain fixed relationship to the reference mark and maycorrespond to the reference point of position of the surface form in themask blank.

A reference mark may be provided on the substrate, the film, or the maskblank and, when acquiring substrate information or film information, theinformation may be produced such that a reference point of positioninformation included in the information has a fixed relationship to thereference mark, thereby making the reference point of position of themask blank information and the reference point of position of theprovided mask blank correspond to each other.

It is preferable that the reference mark be provided so as to be capableof specifying the orientation or the direction of the substrate or themask blank.

The reference mark is preferably provided at a portion adjacent to acorner of the substrate or the mask blank. In the case of providingreference marks at portions in even number, by arranging that one of thereference marks is not provided at a rotation-symmetric position of theother mark when seeing the substrate or the mask blank in a plan view,the direction or the directivity of the substrate or the mask blank canbe easily specified, which is thus preferable.

The reference mark may have a shape that can specify the directivity ofthe substrate.

The reference marks may be provided at asymmetric positions with respectto a line parallel to a side of the substrate and passing through thecenter of the substrate.

The reference mark may be a notch mark formed on the substrate and/or afilm mark by the thin film formed on the main surface of the substrate.

The substrate information or the film information may be informationacquired in a specific direction on the basis of the reference mark.

There may be provided a film forming process of forming on the substratethe film including the thin film which is to be the transfer pattern anda surface information acquisition process of acquiring surfaceinformation of the film and, in the film forming process and the surfaceinformation acquisition process, the directivity of the substrate or themask blank may be managed on the basis of the reference mark.

In the respective processes for manufacturing the mask blank, whenplacing the substrate or the mask blank in a case for use intransferring the substrate or the mask blank to each process, thedirectivity of the substrate or the mask blank may be managed on thebasis of the reference mark.

In the manner as described above, the directivity of the substrate orthe mask blank is managed as predetermined. That is, if a plurality ofsubstrates or mask blanks are arranged with their directions alignedand, further, also when acquiring information, if a plurality ofsubstrates or mask blanks are aligned in the fixed direction to therebyacquire the information, it is preferable for this invention.

The surface information may include at least one of the surfaceinformation of the substrate and the surface information of the film.

The surface information of the film may include surface information of aphase shift film.

The surface form may include surface roughness or waviness, a convexportion and/or a concave portion, foreign matter or a hollow, or filmfall-off which may cause pattern formation failure when fabricating atransfer mask from the mask blank by patterning the thin film, andfurther, may include a particle-shaped defect and/or a pinhole-shapeddefect caused by a defect inspection apparatus.

The surface information may include information about the height,wavelength, and period of the roughness or waviness, the height and sizeof the convex portion, the depth and size of the concave portion, theheight and size of the foreign matter, the depth and size of the hollow,the height and size of the particle, or the depth and size of thepinhole.

The pattern may have a dense pattern forming region where a relativelydense pattern is formed and a sparse pattern forming region where arelatively sparse pattern is formed.

The sparse pattern forming region may be a monitor chip forming regionformed for testing electrical properties.

The transfer mask may be a system LSI manufacturing transfer mask.

A plurality of mask blanks and mask blank information corresponding tothe respective mask blanks may be provided to a mask fabricator.

Further, this invention provides a mask blank dealing system forcarrying out the foregoing mask fabrication supporting method, the maskblank dealing system characterized by directly or indirectly assigning,to a plurality of mask blanks to be delivered to a mask maker,management numbers or management symbols adapted to specify therespective mask blanks, wherein mask blank information is provided tothe mask maker along with the mask blanks while being correlated withthe management numbers or the management symbols.

The management numbers or the management symbols may be slot numbers anda case number assigned to a holder formed with slots for holding themask blanks and a receiving case receiving the holder therein.

The mask blank information may be provided to the mask maker by the useof a communication line.

The mask blank information may be stored in information storage means(server) while being correlated with the management numbers or themanagement symbols and the mask maker may access the information storagemeans (server) by the use of the communication line to obtain the maskblank information based on the management numbers or the managementsymbols.

Further, this invention provides a mask blank manufacturing methodcomprising a process of preparing a substrate for a mask blank, a filmforming process of forming a film including a thin film, which is to bea transfer pattern, on the main surface of the substrate, a surfaceinformation acquisition process of acquiring surface information of themask blank necessary for specifying a region to be subjected to patternformation in order to suppress pattern formation failure whenfabricating a transfer mask by patterning the thin film, and a surfaceinformation storing process of recording and storing the surfaceinformation in an information storage medium, the mask blankmanufacturing method characterized by providing a reference mark on thesubstrate or over the substrate and acquiring the surface information ina specific direction on the basis of the reference mark.

The reference mark may have a shape that can specify the directivity ofthe substrate.

The reference marks may be provided at asymmetric positions with respectto a line parallel to a side of the substrate and passing through thecenter of the substrate.

The reference mark may be a notch mark formed on the substrate and/or afilm mark by the thin film formed on the main surface of the substrate.

In the respective processes for manufacturing the mask blank, whenplacing the substrate in a case for use in transferring the substrate toeach process, the directivity of the substrate may be managed on thebasis of the reference mark.

After preparing the substrate for the mask blank, there may be provideda management number assigning process of directly or indirectlyassigning a management number, adapted to specify the substrate, to thesubstrate for the mask blank, and the surface information of themanufactured mask blank may be collated based on the assigned managementnumber.

Further, there may be provided a packaging process of placing the maskblank in a receiving case and packaging it, wherein the mask blank maybe placed while being held by a holder formed with a slot adapted tohold the mask blank placed in the receiving case and being directly orindirectly assigned mask blank specifying means for identifying the maskblank and the surface information.

The mask blank specifying means may be a slot number and a case numberassigned to the holder and the receiving case.

Further, this invention provides a transfer mask manufacturing method ofusing a mask blank formed on a substrate with a film including at leasta thin film which is to be a transfer pattern and patterning the thinfilm according to pattern data to be formed, thereby fabricating atransfer mask, the transfer mask manufacturing method characterized bycollating surface information of the mask blank correlated with theposition of the surface form in the mask blank and acquired by theforegoing mask fabrication supporting method and the pattern data and,in order to suppress pattern formation failure, specifying a region tobe subjected to pattern formation in the mask blank.

The pattern data has a dense pattern forming region where a relativelydense pattern is formed and a sparse pattern forming region where arelatively sparse pattern is formed. When the surface informationincludes a surface form that will cause pattern failure, the surfaceinformation and the pattern data may be collated to specify thearrangement of the pattern data with respect to the mask blank so thatthe surface form that will cause the pattern failure is located outsidethe dense pattern forming region.

Further, this invention provides a transfer mask manufacturing method ofusing a mask blank formed on a substrate with a film including at leasta thin film which is to be a transfer pattern and patterning the thinfilm according to pattern data to be formed, thereby fabricating atransfer mask, the transfer mask manufacturing method characterized by,before applying the patterning process to the mask blank, collating maskblank information relating to the mask blank acquired by the maskfabrication supporting method of this invention and the pattern dataand, in order to suppress pattern formation failure and/or in order toprevent impediment of a function of the transfer mask, selecting aregion in the mask blank where the pattern is to be formed.

The pattern data includes a region having a relatively dense pattern anda region having a relatively sparse pattern. When the mask blankinformation includes state information, i.e. form information, opticalproperty information, or the like, that will cause pattern failure orthat will cause impediment of the function of the transfer mask, it ispossible to select a position other than a position where such a stateis present and locate the region where the relatively dense pattern isformed.

Further, this invention provides a transfer mask fabrication supportingmethod for supporting a transfer mask fabricator, which uses a maskblank formed on a substrate with a film including at least a thin filmthat is to be a transfer pattern and patterns the thin film according topattern data to be formed, thereby fabricating a transfer mask, wherein,before applying the patterning process to the mask blank, mask blankinformation relating to the mask blank acquired in advance by thisinvention and the pattern data are collated and a region in the maskblank where the pattern is to be formed is selected so as to suppresspattern formation failure and/or prevent impediment of a function of thetransfer mask.

Further, this invention provides a transfer mask fabrication supportingmethod for supporting a transfer mask fabricator, which uses a maskblank formed on a substrate with a film including at least a thin filmthat is to be a transfer pattern and patterns the thin film according topattern data to be formed, thereby fabricating a transfer mask, wherein,before applying the patterning process to the mask blank, mask blankinformation relating to the mask blank acquired in advance by thisinvention and the pattern data are collated and a specific mask blank isselected so as to suppress pattern formation failure and/or preventimpediment of a function of the transfer mask.

The sparse pattern forming region may be a monitor chip forming regionformed for testing electrical properties.

The transfer mask may be a system LSI manufacturing transfer mask.

Further, this invention may be a mask blank providing method ofproviding the foregoing mask fabrication supporting method along withthe mask blank to a mask maker, wherein the mask blank may be placed ina receiving case, and the directivity of the mask blank placed in thereceiving case and the directivity of the substrate in the surfaceinformation acquisition process of acquiring the surface information maybe correlated by a reference mark.

In the respective processes for manufacturing the mask blank, whenplacing the substrate in a case for use in transferring the substrate toeach process, the directivity of the substrate may be managed on thebasis of the reference mark.

The mask blank information acquisition method of this invention can alsobe said as follows.

That is, this invention provides a mask blank information acquisitionmethod for acquiring mask blank information being information relatingto a mask blank having a plurality of films stacked on a surface of asubstrate, the method characterized in that the mask blank informationincludes substrate information and one or more film information or twoor more film information, the substrate information includes positioninformation in a plane coordinate system (two-dimensional coordinatesystem) corresponding to the surface of the substrate and stateinformation indicating a state of the substrate correlated with theposition information, the film information each includes positioninformation in a plane coordinate system corresponding to thecorresponding one of the films and state information indicating a stateof the film correlated with the position information, and the planecoordinate system of the substrate information or the film informationincluded in the mask blank information has a predetermined correlation.

For example, it may be carried out so as to include a step of forming afirst film on the surface of the substrate or on another film formed onthe surface of the substrate, a step of acquiring first film informationrelating to a state of the first film formed, a step of forming a secondfilm on the first film, a step of acquiring second film informationrelating to the second film formed, and a step of producing mask blankinformation including the first film information and the second filminformation.

Alternatively, there may be included a step of preparing the substrate,a step of acquiring substrate information relating to a state of thesubstrate prepared, a step of forming a film on the surface of thesubstrate, a step of acquiring film information relating to a state ofthe film formed, and a step of producing mask blank informationincluding the substrate information and the film information.

Reference points of the plane coordinate systems included in thesubstrate information and the film information may have a predeterminedrelationship to each other or may be determined on the basis of at leastone of a mark formed at the substrate and a mark formed at the film.

There may be further included a step of collating the substrateinformation and/or the film information with each other.

The state information may include at least one of surface forminformation and optical property information.

At least one of the films may be a phase shift film adapted to shift aphase of exposure light.

The mask blank information may include information produced byprojecting the film information of the plurality of films onto a plane.

In order to assign, to the substrate, information indicating thedirection of the substrate, various techniques are considered. Forexample, there may be further included a step of providing a detectablereference mark as state information at a predetermined position on thesubstrate and/or the film before acquiring the film information, whereinthe mask blank information may include information indicating adirection of the substrate determined on the basis of the referencemark. The reference mark may have a shape that can specify a direction.The profile of the substrate may have a shape having rotation symmetry,while, the shape of the substrate including the reference mark providedhas rotation asymmetry. The typical profile of the substrate isrectangle including square and oblong.

When providing the reference mark, there may be included a step offorming a film a on the substrate by an apparatus A and measuring thefilm a to acquire film information a including the reference mark, astep of removing the substrate from the apparatus A, a step of placingthe substrate in a case while aligning the substrate in a predetermineddirection on the basis of the reference mark, a step of transferring thecase to an apparatus B, a step of setting the substrate in the apparatusB while aligning the substrate in a predetermined direction on the basisof the reference mark, and a step of forming a film b on the substrateby the apparatus B and measuring the film b to acquire film informationb including the reference mark.

When providing the reference mark, there may be included a step ofsetting the substrate in a measuring apparatus to measure the substrate,thereby acquiring the substrate information including the referencemark, a step of removing the substrate from the measuring apparatus, astep of placing the substrate in a case while aligning the substrate ina predetermined direction on the basis of the reference mark, a step oftransferring the case to an apparatus A, a step of setting the substratein the apparatus A while aligning the substrate in a predetermineddirection on the basis of the reference mark, and a step of forming afilm a on the substrate by the apparatus A and measuring the film a toacquire film information a including the reference mark.

The mask blank individual may be identified by referring to the acquiredmask blank information.

The state information may include at least two kinds of measurementvalues.

At least one of the substrate information and the film information mayinclude position information in a three-dimensional coordinate systemfurther including coordinates in a thickness direction of the substrateor the film.

Further, this invention provides a mask blank information providingmethod for providing mask blank information being information relatingto a mask blank fabricated by stacking a plurality of films on asubstrate, the method characterized by providing the mask blankinformation acquired by the foregoing mask blank information acquisitionmethod, along with the mask blank.

Further, this invention provides a transfer mask fabrication supportingmethod for supporting fabrication of a transfer mask by providing maskblank information to a mask maker, the method characterized bycomprising a step of providing the mask blank information to the maskmaker by the foregoing mask blank information providing method, wherein,in order to prevent fabrication of a defective transfer mask, the maskblank information provided is referred to for specifying a region on thecorresponding mask blank where a mask pattern is to be formed, beforeforming the mask pattern on the mask blank.

Further, this invention provides a transfer mask fabrication supportingmethod for supporting fabrication of a transfer mask by providing maskblank information to a mask maker, the method characterized bycomprising a step of providing the mask blank information to the maskmaker by the foregoing mask blank information providing method, whereina reference point of a coordinate system in the mask blank informationis notified to the mask maker through the reference mark, and the maskmaker provided with the mask blank information acquires the correlationbetween the plane coordinate systems through the reference mark anddetermines a region, where a mask pattern is to be formed, based on theacquired correlation and the mask blank information.

In this transfer mask fabrication supporting method, the mask patternformed on the mask blank may include a relatively dense pattern blockand a relatively sparse pattern block.

Further, this invention provides a transfer mask manufacturing methodfor manufacturing a transfer mask by forming a mask pattern, which is tobe a transfer pattern, on a mask blank, the method characterized bydetermining a region where the mask pattern is to be arranged on themask blank, based on the mask blank information acquired by theforegoing mask blank information acquisition method.

Further, this invention provides a mask blank manufacturing method formanufacturing a mask blank, the method characterized by including theforegoing mask blank information acquisition method.

Further, this invention provides a mask blank information acquisitionsystem for acquiring mask blank information being information relatingto a mask blank having a plurality of films stacked on a surface of asubstrate, the system characterized by comprising at least twoinformation acquisition means among means for acquiring substrateinformation relating to a state of the substrate, means for acquiringfirst film information relating to a state of a first film formed on thesurface of the substrate or on another film formed on the surface of thesubstrate, and means for acquiring second film information relating to astate of a second film being a film other than the first film formed onthe surface of the substrate, and further comprising means for producingmask blank information including the information acquired by theinformation acquisition means.

In this mask blank information acquisition system, the substrateinformation may include position information in a plane coordinatesystem corresponding to the surface of the substrate and stateinformation indicating a state of the substrate correlated with theposition information, the film information may include positioninformation in a plane coordinate system corresponding to the film andstate information indicating a state of the film correlated with theposition information, and the plane coordinate system of the substrateinformation or the film information included in the mask blankinformation may have a predetermined correlation.

In the foregoing mask blank information acquisition method, thesubstrate may have a polygonal shape and the reference mark may beprovided in a region sandwiched between mutually contacting two sides ofthe substrate.

In the foregoing mask blank information acquisition method, the evennumber of reference marks may be provided at mutually rotationasymmetric positions.

Further, this invention provides a transfer mask fabrication supportingmethod for supporting fabrication of a transfer mask by providing maskblank information to a mask maker, the method characterized bycomprising a step of providing mask blank information of a plurality ofmask blanks to the mask maker by the foregoing mask blank informationproviding method, wherein the mask blank information provided isreferred to for selecting one of the plurality of mask blanks beforeforming a mask pattern.

In the foregoing mask blank information acquisition method, there may befurther included, after the step of acquiring the film information b, astep of placing the substrate in a case while aligning the substrate ina predetermined direction on the basis of the reference mark.

In the foregoing mask blank information acquisition method, there may befurther included, after the step of acquiring the film information a, astep of placing the substrate in a case while aligning the substrate ina predetermined direction on the basis of the reference mark.

This invention provides a mask blank providing method for providing amask blank, the method characterized by providing, along with a maskblank, mask blank information relating to the mask blank acquired by theforegoing mask blank information acquisition method.

Effect of the Invention

Through the manufacture of a mask blank, the directions of substrateinformation and film information and the direction of an actualsubstrate can be made consistent with each other. Further, even if thesubstrate is handled in a wrong direction during the manufacture, thedirection error can be detected by comparing the substrateinformation/film information with each other.

Based on the acquired substrate information/film information, the maskblank can be individually identified. That is, the substrateinformation/film information can be used as a kind of identifier.

By providing the substrate information and the film informationcorresponding to the direction of the substrate, it is possible toaccurately transmit the positions of defects existing in the respectivesubstrate and film layers of the mask blank.

Since the defects of the respective layers of the mask blank can beaccurately transmitted, it becomes possible to fabricate a mask whileavoiding defect portions, so that pattern failure of the mask can beprevented.

Further, even if there exists a portion having defects, depending on thekind/size/number etc. thereof and the shape/density etc. of a pattern tobe written, it is possible to judge in advance that writing of thepattern causes no problem and, hence, the effective utilization of maskblanks can be achieved.

BRIEF DESCRIPTION OF THE INVENTION

FIG. 1 is a flowchart for explaining a mask blank film informationacquisition method of this invention.

FIG. 2A is a sectional view for explaining a mask blank receiving case10.

FIG. 2B is a plan view for explaining the mask blank receiving case 10.

FIG. 3A is a diagram for explaining tray marks 31 indicating thefront/back of a mask blank.

FIG. 3B is a diagram for explaining notch marks 1 indicating thefront/back of the mask blank.

FIG. 4 is a graph for explaining one example of mask blank filminformation (surface information) acquired by a mask blank filminformation (surface information) acquisition process of this invention.

FIG. 5 is a block diagram for explaining a mask blank film informationmanagement system 50 of this invention.

FIG. 6 is a block diagram for explaining a host computer 51.

FIG. 7 is a block diagram for explaining a cassette number/slot numberassigner 52.

FIG. 8 is a block diagram for explaining a first film forming apparatus53.

FIG. 9 is a block diagram for explaining a first film defect inspectionapparatus 54.

FIG. 10 is a block diagram for explaining a resist film formingapparatus 57.

FIG. 11 is a block diagram for explaining a mask fabrication supportingsystem 110.

FIG. 12 is a flowchart for explaining a pattern writing/developmentprocess in the mask manufacturing process in an orderer/mask factory 12.

FIG. 13A is a sectional view of a mask blank before being subjected tothe writing/development process in the mask manufacturing process.

FIG. 13B is a sectional view of a transfer mask fabricated through themask manufacturing process.

FIG. 14 is a diagram for explaining the arrangement of a sparse patternforming region and a dense pattern forming region carried out based onblank film information and mask pattern data.

FIG. 15 is a flowchart for explaining mask blank manufacturing processesand a method of acquiring and storing mask blank film information in themanufacture of a mask blank, in a mask fabrication supporting method ofthis invention.

FIG. 16A is a diagram for explaining notch marks 1 of a mask blank.

FIG. 16B is a diagram for explaining film marks 31 of the mask blank.

FIG. 17 is a graph for explaining one example of mask blank filminformation (surface information) acquired by a mask blank filminformation (surface information) acquisition process of this invention.

FIG. 18A is a sectional view for explaining a receiving case 10 forreceiving mask blanks therein.

FIG. 18B is a plan view for explaining the receiving case 10 forreceiving mask blanks therein.

FIG. 19 is a block diagram for explaining a mask fabrication supportingsystem 110.

FIG. 20 is a flowchart for explaining a mask manufacturing processincluding a process in which a mask factory 112 applies awriting/development process to a resist film of a mask blank by the useof blank film information, thereby forming a pattern.

FIG. 21A is a sectional view of the mask blank before carrying out thewriting/development process in the mask manufacturing process.

FIG. 21B is a sectional view of a transfer mask fabricated through themask manufacturing process.

FIG. 22 is a diagram for explaining the arrangement of a sparse patternforming region and a dense pattern forming region carried out based onblank film information and mask pattern data.

FIG. 23 is a block diagram for explaining a mask blank film informationmanagement system 50 of this invention.

FIG. 24 is a block diagram for explaining a cassette number/slot numberassigner 52.

FIG. 25 is a block diagram for explaining a host computer 51.

FIG. 26 is a block diagram for explaining a first film forming apparatus53.

FIG. 27 is a block diagram for explaining a first film defect inspectionapparatus 54.

FIG. 28 is a block diagram for explaining a resist film formingapparatus 57.

DESCRIPTION OF SYMBOLS

-   1 notch mark-   2 distribution case-   2′, 4′, 5′, 7′, 8′, 9′, 10′ ID tag-   3, 6, 31 film mark-   4, 5, 7, 8, 9, 10 distribution case-   20 receiving case-   21 case number-   22 lid-   23 outer box-   24 innerbox-   25 slot-   26 front indication-   50 mask blank production line control system-   51 host computer-   52 cassette number/slot number assigner-   53 first film forming apparatus-   54 first film defect inspection apparatus-   55 second film forming apparatus-   56 second film defect inspection apparatus-   57 resist film forming apparatus-   58 resist film defect inspection apparatus-   110 mask fabrication supporting system-   111 mask blank factory-   112 mask factory-   113 data communication line (Internet)-   114 server-   142 mask pattern-   143 dense pattern forming region-   144 sparse pattern forming region-   511 data transmission/reception section-   512 process flow storage section-   513 information storage section-   514 defect information collation section-   521 input section-   522 data transmission/reception section-   531 loader port-   532 data transmission/reception section-   533 recipe number-sputtering condition collation section-   534 sputtering condition storage section-   535 sputtering condition control section-   536 sputtering apparatus-   537 slot number, sputtering result, unloader slot number collection    section-   538 unloader port-   541 data transmission/reception section-   542 cassette number-recipe number collation section-   543 loader port-   544 defect inspection condition storage section-   545 defect inspection condition control section-   546 defect inspection apparatus-   547 unloader port-   548 unloader cassette number, unloader slot number assigning portion-   571 data transmission/reception section-   572 loader port-   573 RC recipe number-resist coating condition, resist heating    condition, resist cooling condition collation section-   574 resist coating condition, resist heating condition, resist    cooling condition storage section-   575 resist coating condition, resist heating condition, resist    cooling condition control section-   576 resist coating apparatus-   577 heater-   578 cooler-   579 unloader port-   580 slot number, resist coating result, unloader slot number    assigning section

MODE FOR CARRYING OUT THE INVENTION

Description will be made about a mask blank film information acquisitionmethod being a first embodiment of this invention. In the followingdescription embodiment, film information includes surface information asdescribed above and can be read as surface information as it is.

The mask blank film information acquisition method is carried out inparallel with processes in which a mask blank is manufactured by forminga first film, a second film, and a resist film on a glass substrate andthen is placed in a receiving case. Each time the first film, the secondfilm, and the resist film are each formed, an inspection of the film iscarried out so that first-film film information, second-film filminformation, or resist-film film information is produced according tothe result thereof and registered in a host computer. The host computercollects these film information to produce and store mask blank filminformation and outputs the stored mask blank film information topaper/electronic medium/communication line or the like in response to arequest from the exterior.

Referring to FIG. 1, this figure is divided into upper, middle, andlower three stages by dotted lines. The lower stage shows the processflow, the middle stage shows mask blanks in the manufacturecorresponding to respective processes, and the upper stage shows filminformation produced in inspection processes. Hereinbelow, descriptionwill be given along the process flow of the lower stage.

(1) Substrate Processing Process

Glass substrates formed with notch marks 1 are prepared. The notch markindicates the kind of glass of the substrate by its shape. Then, thesurfaces of each glass substrate are ground/polished so as to befinished to a predetermined surface roughness and flatness. Aftercleaning the glass substrate for removing abrasives used in thepolishing process, the glass substrate is placed in a distribution case2 with an ID tag attached. In the distribution case 2, the glasssubstrate is placed with its direction aligned on the basis of the notchmark 1.

(2) First Film Forming Process

By the use of a host computer that carries out production management,the ID tag attached to the distribution case 2 is assigned managementnumbers serving to manage the respective substrates. The host computercollects information about manufacturing process order, manufacturingcondition setting, and respective manufacturing processes andrecords/stores it. The glass substrate placed in the distribution case 2is transferred into a sputtering apparatus where a MoSiN halftone filmbeing a first film is formed by reactive sputtering on the glasssubstrate on its side opposite to its side where the notch marks 1 areformed. In this event, film marks 3 are formed at positions where theMoSiN film is not formed due to a substrate holder. The MoSiN halftonefilm coated substrate is placed in a distribution case 4 different fromthe distribution case 2. Along with this, information of the completionof the first film formation is stored in the host computer. Themanagement number is transferred to an ID tag attached to thedistribution case 4. In the distribution case 4, the substrate is placedwith its direction aligned on the basis of the notch mark 1 (or the filmmark 3).

(3) First Film Inspection Process

The halftone film coated substrate placed in the distribution case 4 istransferred into a defect inspection apparatus that inspects a defect ofthe first film, where a defect inspection is carried out to acquire filminformation. As the film information (film surface information),position information of a defect, the size of a defect (the size isindicated by rank), and the type of a defect (pinhole, particle, or thelike) are stored in the host computer per management number. The filminformation acquired here is called first-film film information. Thesubstrate having been subjected to the defect inspection is placed in adifferent distribution case 5. Along with this, the management number istransferred to an ID tag of the distribution case 5. In the distributioncase 5, the substrate is placed with its direction aligned on the basisof the notch mark 1 (or the film mark 3).

(4) Second Film Forming Process

The halftone film coated substrate placed in the distribution case 5 istransferred into an in-line sputtering apparatus where a Cr lightshielding film being a second film is formed on the first film byreactive sputtering. In this event, film marks 6 are formed at positionswhere the Cr film is not formed due to a substrate holding portion. TheCr light shielding film coated substrate is placed in a differentdistribution case 7. Along with this, information of the completion ofthe second film formation is stored in the host computer. The managementnumber is transferred to an ID tag attached to the distribution case 7.In the distribution case 7, the substrate is placed with its directionaligned on the basis of the notch mark 1 (or the film mark 3 or 6).

(5) Second Film Inspection Process

The Cr light shielding film coated substrate placed in the distributioncase 7 is transferred into a defect inspection apparatus that inspects adefect of the second film, where a defect inspection is carried out toacquire film information (film surface information). As the filminformation, position information of a defect, the size of a defect (thesize is indicated by rank), and the type of a defect (pinhole, particle,or the like) are stored in the host computer per management number. Thefilm information acquired here is called second-film film information.The substrate having been subjected to the defect inspection is placedin a different distribution case 8. Along with this, the managementnumber is transferred to an ID tag attached to the distribution case 8.In the distribution case 8, the substrate is placed with its directionaligned on the basis of the notch mark 1 (or the film mark 3 or 6).

(6) Resist Film Forming Process

The Cr light shielding film coated substrate placed in the distributioncase 8 is transferred into a spin coating apparatus where a resist filmis coated on the second film by a spin coating method, thereby formingthe resist film through baking and cooling. The resist film coatedsubstrate (mask blank) is placed in a different distribution case 9.Along with this, information of the completion of the resist filmformation is stored in the host computer. The management number istransferred to an ID tag attached to the distribution case 9. In thedistribution case 9, the mask blank is placed with its direction alignedon the basis of the notch mark 1 (or the film mark 3 or 6).

(7) Resist Film Inspection Process

The resist film coated substrate (mask blank) placed in the distributioncase 9 is transferred into a defect inspection apparatus where a defectinspection is carried out to acquire film information. As the filminformation, position information of a defect, the size of a defect (thesize is indicated by rank), and the type of a defect (pinhole, particle,or the like) are stored in the host computer per management number. Thefilm information acquired here is called resist-film film information.The substrate having been subjected to the defect inspection is placedin a different distribution case 10. Along with this, the managementnumber is transferred to an ID tag attached to the distribution case 10.In the distribution case 10, the mask blank is placed with its directionaligned on the basis of the notch mark 1 (or the film mark 3 or 6).

(8) Film Information Collation Process

The first-film film information, the second-film film information, andthe resist-film film information are collated with each other, therebyconfirming whether the directions coincide among the film information.

Specifically, the defect information data of the respective films arecollated with each other on the basis of defects that do not change inposition. This utilizes the fact that when a defect exists in the firstfilm being a film at the lowermost layer, defects also occur in thesecond film and the resist film being films at layers above the firstfilm, thereby judging based on the first-film film information whetheror not the directions of the other film information are correct.

By this, the directions can be made consistent among the filminformation. However, for example, there is a possibility that whenmoving a substrate from a certain distribution case to anotherdistribution case, the substrate may be placed in the distribution casewith its direction being wrong. In this case, even if the directionsagree among the film information, the directions of the film informationand the substrate disagree.

In order to avoid such a possibility, when placing or removing asubstrate in or from a distribution case or a receiving case, anoperator refers to the notch mark 1 or the film mark 3 or 6 as the basisfor the direction of the substrate and places or removes the substratealong a predetermined direction.

By this, the direction of the substrate in the mask blank manufacturingprocesses (1) to (9) can be kept constant so that it is possible toavoid disagreement between the directions of the substrate and the filminformation and make the directions consistent among the filminformation, and hence, the direction of the substrate and all the filminformation directions can be made consistent with each other. Further,since the consistency among the film information is confirmed, even ifthe substrate is placed in a distribution case or a receiving case withits direction being wrong in the manufacturing process, it can bedetected.

(9) Blank Packaging Process

The mask blanks are placed in a receiving case 20 and packaged, and thendelivered to a mask maker.

Herein, the receiving case 20 will be described with reference to FIGS.2A and 2B. A unique case number 21 is assigned and attached to each ofreceiving cases 20. The receiving case 20 comprises a lid 22 and anouter box 23 and further comprises an inner box 24 and slots 25 in theouter box 23. The inner box 24 is received in the outer box 23 andserves as a substrate holder. Although the slot 25 is a partitionbetween the substrates, a portion between the adjacent two slots 25 forstoring the substrate will also be called a slot hereinbelow for thesake of explanation. In this sense, there are slots for storing fivesubstrates in FIG. 2B. The slots are assigned slot numbers and calledslot No. 1, slot No. 2, . . . slot No. 5, respectively. Among outersurfaces of the outer box 23, a front indication 26 showing thedirection of the receiving case 20 is described on the surface close toslot No. 1. The case number and the slot number are combined to identifya mask blank stored in the receiving case 20.

For correlation between the reference point of the position informationof the film information in each mask blank and the reference point ofeach mask blank placed in the receiving case 20 for correlation with theforegoing reference point of the position information, when placing eachmask blank in the receiving case 20, it is placed with its directivityaligned on the basis of the foregoing notch mark 1 (or the film mark 3or 6). As described above, in each of the mask blank manufacturingprocesses, the film formation or the defect inspection is carried outwhile aligning the directivity of the substrate on the basis of thenotch mark 1 (or the film mark 3 or 6) and, further, also in thesubstrate distribution case used for transferring the substrate betweenthe respective processes, the substrate is placed with its directivityaligned on the basis of the notch mark 1 (or the film mark 3 or 6) and,also when providing the mask blank to the mask maker while placing it inthe receiving case, the mask blank is placed with its directivityaligned on the basis of the notch mark 1 (or the film mark 3 or 6), sothat the mask blank and the position information of the defectinformation can be accurately correlated with each other to therebyprevent pattern failure in the mask fabrication.

Referring back to the description of the blank packaging process, inthis event, the blank film information including the first-film filminformation, the second-film film information, and the resist-film filminformation is provided per corresponding mask blank to the mask makerat the delivery destination. As blank film information providingmethods, there are (a) attaching a print printed with the blank filminformation to the receiving case 20, (b) attaching to the receivingcase 20 a recording medium such as a flexible disk or a CD-ROM recordingthe blank film information data, (c) transmitting the blank filminformation data to a computer or the like of the mask maker at thedelivery destination through a data communication line, and so on. Inthe case of (a) or (b), the blank film information itself is attached tothe receiving case 20 along with a correlation with slot numbers. In thecase of (c), the mask maker transmits a case number and a slot numberand receives the corresponding blank film information.

A cleaning process may be provided between the first film formingprocess and the first film inspection process and between the secondfilm forming process and the second film inspection process.

In the foregoing processes (1) to (10) and further in the mask maker,the front and back of the mask blank are identified by film marks 31 andnotch marks 1 as shown in FIGS. 3A and 3B. On the front surface shown inFIG. 3A, the film marks 31 are given. On the back surface shown in FIG.3B, the notch marks 1 are given.

Each film information comprises X and Y coordinates of an XY coordinatesystem predetermined on a film on the basis of a predetermined directionof a substrate, the size of a defect, and the type of a defect. Thedefect types comprise a pin hole and a particle. The particle representsa state where a granular substance is adhered on the film, while, thepinhole represents a state of a trace where a granular substance onceadhered has fallen off.

FIG. 4 shows an example of blank film information. It is understood thatwhen a defect exists at a position at the stage of a first film, defectsoccur at the same positions of both a second film and a resist film.

Next, description will be made about a mask blank production linecontrol system 50 being a second embodiment of this invention. Referringto FIG. 5, the mask blank production control system 50 comprises a hostcomputer 51, a cassette number/slot number assigner 52 (hereinafterreferred to as the assigner 52), a first film forming apparatus 53, afirst film defect inspection apparatus 54, a second film formingapparatus 55, a second film defect inspection apparatus 56, a resistfilm forming apparatus 57, and a resist film defect inspection apparatus58.

A cassette has a plurality of slots for receiving substrates therein andis provided with an ID tag. In the ID tag, a cassette number assigned tothe cassette is recorded.

Referring to FIG. 7, when putting substrates on the production line, thesubstrates are placed in a cassette and a cassette number, slot numbers,and a process flow are input from an input section 521 in the assigner52. The process flow includes a process order, a name of an apparatusfor use in the process, and a recipe number for use in the apparatus andis given per cassette according to masks to be manufactured. On theproduction line, the substrate is identified by the position in theprocesses, the cassette number, and the slot.

The assigner 52 writes the cassette number in an ID tag of the cassetteand, by the use of a data transmission/reception section 522, transmitsthe cassette number, the slot numbers, and the process flow to the hostcomputer 51. Referring to FIG. 6, after reception at a datatransmission/reception section 511, the host computer 51 stores thecassette number, the slot numbers, and the process flow in a processflow storage section 512 while correlating them with each other.

When the cassette finished with the input of the cassette number by theassigner 52 (hereinafter, this cassette will be referred to as thecassette A) is set in a loader port 531 of the first film formingapparatus 53, the first film forming apparatus 53 reads the cassettenumber from the ID tag of the cassette A and notifies it to the hostcomputer 51 by the use of a data transmission/reception section 532.

Referring to FIG. 8, the host computer 51, in response thereto,transmits the cassette number of the cassette A, the slot numbers, andthe recipe number of sputtering to the first film forming apparatus 53.With respect to the recipe number, its transmission may be immediatelybefore the start of operation of a sputtering apparatus.

In the first film forming apparatus 53 in receipt thereof, a recipenumber-sputtering condition collation section 533 identifies asputtering condition corresponding to the recipe number and stores theidentified sputtering condition in a sputtering condition storagesection 534. According to this sputtering condition, a sputteringcondition control section 535 controls a sputtering apparatus 536 tocarry out a sputtering process.

The sputtering apparatus 536 takes the substrate from the cassette A andstarts the sputtering process. During the sputtering process, thesputtering results are collected and correlated with the slot number.

The substrate finished with the sputtering process enters a slot ofanother cassette (hereinafter referred to as the cassette B) prepared inadvance in an unloader port 538. In this event, a slot number,sputtering result, unloader slot number collection section 537(hereinafter referred to as the collection section 537) collects theslot number in the cassette A, the correlated sputtering results, and aslot number in the cassette B and transmits them to the host computer 51by the use of the data transmission/reception section 532. When slots ofthe cassette B are all occupied by the substrates having been subjectedto the first film formation, the collection section 537 notifies thehost computer 51 to that effect as well as of a cassette number of thecassette B.

In response thereto, the host computer 51 specifies the next process interms of the cassette number B, the cassette number A, and the processflow and notifies a transfer destination to a non-illustrated cassettetransfer portion.

Further, the host computer 51 transmits the cassette number of thecassette B and the recipe number of sputtering transmitted to the firstfilm forming apparatus 53, to the first film defect inspection apparatus54.

Referring to FIG. 9, in response to receipt of them at a datatransmission/reception section 541, the first film defect inspectionapparatus 54 gives them to a cassette number-recipe number collationsection 542.

When the cassette is carried into a loader port 543, the cassettenumber-recipe number collation section 542 identifies a recipe numbercorresponding to the cassette number read from an ID tag of thecassette.

Herein, if the cassette number is that of the cassette B, there isobtained the recipe number that was used when the sputtering process wasapplied to the substrates placed in the cassette B.

In a defect inspection condition storage section 544, there is stored inadvance a correlation between recipe numbers and inspection conditionsto be carried out for films formed under recipe conditions indicated bythe recipe numbers. In response to receipt of the recipe number from thecassette number-recipe number collation section 542, the defectinspection condition storage section 544 outputs the inspectioncondition to be carried out.

According to this inspection condition, a defect inspection conditioncontrol section 545 controls a defect inspection apparatus 546 to carryout an inspection. The defect inspection apparatus 546 outputs aninspection result as defect inspection information. The inspectedsubstrate is placed in a slot of another cassette (hereinafter referredto as the cassette C) set in advance in an unloader port 547.

An unloader cassette number, unloader slot number assigning portion 548assigns a cassette number to the cassette C and, by the use of the datatransmission/reception section 541, transmits the cassette number of thecassette C, slot numbers of the cassette C, and the defect inspectioninformation of the substrates placed in the slots to the host computer51 while correlating them with each other.

The host computer 51 stores the transmitted information in aninformation storage section 513 while correlating it with the sputteringresults and so on obtained in the first film forming apparatus 53.

With respect to the second film forming apparatus 55 and the second filminspection apparatus 56, explanation thereof is omitted because, ascompared with the first film forming apparatus 53 and the first filminspection apparatus 54, respectively, there is a difference only due todifference in kind of a film to be formed, but no large difference incomponents and operation. This also applies to the resist film formingapparatus 57 and the resist film defect inspection apparatus 58 shown inFIG. 10.

Based on the information collected from the first film forming apparatus53, the first film inspection apparatus 54, the second film formingapparatus 55, the second film inspection apparatus 56, the resist filmforming apparatus 57, and the resist film inspection apparatus 58 asdescribed above, a defect information collation section 514 produces thefirst-film film information, the second-film film information, and theresist-film film information described in the first embodiment andcollates them with each other to produce the blank film informationshown in FIG. 4.

Next, description will be made about a mask fabrication supportingsystem 110 being a third embodiment of this invention.

Referring to FIG. 11, the mask fabrication supporting system 110comprises a mask blank factory 111, a mask factory 112 that manufacturesmasks based on mask blanks manufactured in the mask blank factory 111,and a data communication line 113 connecting both factories together.Further, the mask blank factory 111 comprises a host computer 51 and aserver 114. The mask blanks manufactured in the mask blank factory 111are delivered to the mask factory 112 while being placed in theforegoing receiving case 10. The host computer 51 is the foregoing hostcomputer 51 of the mask blank production line control system 50. Theserver 114 receives necessary information from the host computer 51 andprovides the information to a computer of the mask factory 112 at aremote place through the Internet 113.

Description will be made about a process of writing a pattern on aresist film of a mask blank in the mask fabrication supporting system110.

As described in the second embodiment, blank film information ofmanufactured mask blanks is stored in the host computer 51 in advance.In the blank film information, its directivity is specified on the basisof a notch mark or a film mark so that its reference point isguaranteed. Further, the manufactured mask blanks are placed in areceiving case 10 such that the directivity of each mask blank isaligned on the basis of the notch mark or the film mark, so as to bedelivered to the mask factory 112. In this event, the receiving case 10is attached with a case number. The attachment of the case number is notlimited to a visible state such as printing, and it may be attached in amechanically readable state such as, for example, a barcode, a magneticrecording medium, or an IC chip.

Referring to FIG. 12, description will be made about a maskwriting/development process in the mask factory 112. An operator, inreceipt of a receiving case 10, in the mask factory 112 acquires a casenumber from the receiving case 10 visually or by mechanical reading andthen, by the use of a data communication apparatus such as a computer,transmits the case number to the server 114 through the datacommunication line 113 such as the Internet.

In response thereto, the server 114 transmits blank film information ofmask blanks placed in respective slots of the receiving case of thatcase number (step S121).

Various manners can be considered as manners of data communication.

For example, transmission of both a case number and blank filminformation may be carried out through electronic mails, or, a databaserepresenting a correlation between case numbers and blank filminformation of mask blanks placed in respective slots of receiving casesof those case numbers may be installed on the server 114 and the blankfilm information corresponding to the case number input from the side ofthe mask factory 112 may be transmitted in reply. At this stage, eachmask blank has a section shown in FIG. 13A, wherein three-layer films,i.e. a first film, a second film, and a resist film, are formed on aglass substrate.

The mask factory 112 in receipt of the blank film information collatesbetween the blank film information and a mask pattern of a mask to bemanufactured (step S122). As described above, in this event, a referencepoint of position information in the mask blank and a reference point ofposition information in the blank film information correspond to eachother. Alternatively, in this event, a reference point of positioninformation in the mask blank and a reference point of positioninformation of mask pattern data correspond to each other.

Now, it is assumed that the mask factory 112 is in receipt of blank filminformation 141 from the mask blank factory 111 and is going to write amask pattern 142. The blank film information 141 includes first-filmfilm information, second-film film information, and resist-film filminformation.

Generally, a mask pattern has a dense pattern forming region 143 wherethe density is high and a sparse pattern forming region 144 where thedensity is low.

On the other hand, generally, pinholes and particles of a mask blank arenot uniformly distributed, but dispersed locally to some extent.Therefore, referring to the blank film information 142, the patternwriting position is determined through adjustment so that pinholes andparticles are located in the region other than the dense pattern formingregion 143 (step S123).

As a pattern writing position adjusting method, it is considered tochange the direction of the mask pattern 142 with respect to thedirection of the substrate. On the other hand, if it is possible tochange the relative position relationship between the dense patternforming region 143 and the sparse pattern forming region 144, theadjustment may be carried out by changing it.

Finally, in accordance with the determined pattern writing position, apattern is written on the resist film and developed (step S124).

Next, a fourth embodiment will be described. In this embodiment, thetechnique of making the directions of blank film information and asubstrate consistent with each other will be particularly taken up anddescribed.

Referring again to FIGS. 1 and 3, the glass substrate of the mask blankis formed with the notch marks 1. In the conventional technique, thenotch mark 1 is intended only for indicating the kind of glass of theglass substrate and indicates the kind of glass of the glass substrateby the difference in its shape.

Further, primarily for the purpose of indicating the kind of film, thefilm marks are formed on the film. Like the notch mark 1, the film markindicates the kind of film by the difference in its shape and theposition relationship between that film and another film. For example,the film mark 2 on the first film has a shape indicative of being theMoSiN film, while, the film mark 3 on the second film has a shapeindicative of being the Cr film. In the figures, the film marks areshown in a simplified manner and hence do not agree with the actualshapes.

In this invention, these notch mark and film marks are used asreferences for the direction of the substrate, thereby always aligningthe substrate in the same direction when placing or removing it in orfrom the container such as the distribution case, the cassette, or thereceiving case. By this, the directions of the first-film filminformation, the second-film film information, and the resist-film filminformation all coincide with the direction of the substrate.

In this embodiment, the number of films of the film information may beone. It is applicable even to the defect information obtained byobserving the surface of the mask blank immediately before shipping fromthe mask blank factory, i.e. observing only the surface film, as seen inthe conventional technique. Even in this case, there is an effect ofensuring the consistency between the direction of the defect informationand the direction of the substrate.

Next, a fifth embodiment of this invention will be described. The fifthembodiment is a modification obtained by changing part of an embodimentwhich collectively includes the foregoing first to fourth embodiments.Hereinbelow, description will be made about a mask blank informationacquisition method, a mask fabrication supporting method, amanufacturing method of a mask blank to be provided to a mask maker, atransfer mask manufacturing method, and a method of acquiring andstoring mask blank information in the manufacture of a mask blank.Further, specific examples of a mask blank information providing methodand a mask blank providing method will also be disclosed.

In the following description of the embodiment, film informationincludes surface information and can be read as surface information.

The film information is plane information acquired by scanning thesurface of a film. On the other hand, substrate information is planeinformation acquired by scanning the surface of a substrate. The planeinformation is information that can be comprehended by projecting itonto the plane coordinates being the two-dimensional coordinates.

Hereinbelow, there will be shown an example of acquiring substrateinformation or film information by the use of a defect inspection,wherein a defect represents a surface form or optical property thatimpedes the function of a transfer mask or causes an inferior transfermask. Specifically, a particle-shaped defect and a pinhole-shaped defectcan be cited as examples.

As shown in FIG. 15, mask blank information is acquired utilizinginspection processes that are carried out in parallel with processes inwhich a mask blank is manufactured by forming thin films, i.e. a firstfilm, a second film, and a resist film, respectively, on a glasssubstrate and then is placed in a case. Although a substrate inspectionis not shown in the example of FIG. 15, substrate information can beacquired by preparing the glass substrate having been subjected toprocessing such as mirror polishing and carrying out the substrateinspection prior to forming the first film.

In the embodiment shown in FIG. 15, each time the thin films, i.e. thefirst film, the second film, and the resist film, are each formed, adefect inspection of the thin film is carried out. Film information ofthe first film, film information of the second film, and filminformation of the resist film are produced according to the inspectionresults and then recorded and stored in a host computer while beingcorrelated with each substrate (each mask blank). Thereafter, thesubstrate information and the film information recorded and stored inthe host computer are collated to collectively produce mask blankinformation.

The mask blank information is produced by combining a plurality of planeinformation such as the substrate information, the first-film filminformation, the second-film film information, and the resist-film filminformation. The plurality of plane information forming the mask blankinformation are information relating to different sections of the samemask blank, respectively. Therefore, the mask blank information servesas information three-dimensionally showing the state of the inside ofthe mask blank.

The mask blank information is provided to a mask maker while beingcorrelated with each of the mask blank individuals manufactured throughthe mask blank manufacturing processes and placed in a receiving case20. The information is provided to the mask maker from a mask blankmaker by the use of a paper document, an electronic medium, a magneticmedium, a communication line, or the like.

Referring to FIG. 15, this figure is divided into upper, middle, andlower three stages by dotted lines. The lower stage of FIG. 15 shows themask blank manufacturing processes and the directivity of placement of asubstrate or a mask blank in a cassette used for transferring thesubstrate between the respective processes, i.e. the longitudinal andlateral directions.

The middle stage of FIG. 15 shows the structures of films and the formsof film-coated substrates in the manufacture corresponding to respectiveprocesses. The upper stage of FIG. 15 shows the film informationproduced in the defect inspection processes. Hereinbelow, the method ofacquiring and storing the film information will be described in detailalong the flow of the mask blank manufacturing processes of the lowerstage.

(1) Substrate Processing Process

Glass substrates formed with notch marks 1 are prepared. By the notchmark, the kind of glass of the glass substrate can be distinguished.

For example, the notch mark 1 has a plane shape formed by cutting inoblique section, at a corner of the glass substrate, three surfaces,i.e. the main surface and two end surfaces forming the corner, as shownin Japanese Unexamined Utility Model Application Publication (JP-U) No.S62-17948. The number of formed notch marks and the formed positions canalso be used for distinguishing the kind of glass forming the glasssubstrate.

In the embodiment of this invention, the notch mark 1 serves as areference mark for specifying the directivity of the substrate and alsoserves as a reference point in film information acquired in thelater-described defect inspection processes.

As a specific example, notch marks 1 can be provided at two corners of asubstrate on one main surface side thereof as shown in FIG. 16A. Thekind of glass of this glass substrate formed with the notch marks 1 atthe diagonal positions is a synthetic quartz glass.

Then, the surfaces of each glass substrate are ground/polished so as tobe finished to a predetermined surface roughness and flatness. Further,the glass substrate is cleaned for removing abrasives used in thepolishing process.

Then, the glass substrate is placed in an in-process distributioncassette 2 with an ID tag 2′ attached. Hereinafter, this cassette willbe referred to as the distribution cassette 2. This ID tag isinformation management means that can write or read information about adistribution cassette and substrates or mask blanks placed in thedistribution cassette. The ID tag is a medium that can record and holdinformation. For example, an IC tag can be used.

The ID tag can be assigned and hold management numbers, for example,identification numbers, adapted to manage the respective substrates ormask blanks placed in the distribution cassette.

The management numbers include a cassette number assigned perdistribution cassette and slot numbers assigned corresponding to aplurality of grooves provided for receiving a plurality of substrates inthe distribution cassette. Based on the management numbers, therespective substrates can be identified and managed.

The management numbers assigned to the ID tag serve to correlateinformation of the respective processes acquired in the subsequentprocesses, for example, film information produced in the inspectionprocesses of respective thin films, manufacturing conditions andmanufacturing recipes used in the forming processes of respective thinfilms, and so on, with the respective substrates.

The distribution cassette 2 is configured so that the direction of thecassette, i.e. the front, back, left, and right of the cassette, can bedistinguished. Further, a plurality of grooves each extending verticallyare formed at predetermined intervals on two facing inner walls of thedistribution cassette 2 so that the glass substrates or mask blanks canbe placed in the respective grooves. In these plurality of grooves, theglass substrates or mask blanks are placed with their directions alignedon the basis of the notch marks 1.

Specifically, the glass substrates or mask blanks are placed so that thenotch marks 1 formed on the glass substrates are arranged in apredetermined relationship to a-predetermined position of thedistribution cassette 2. The plurality of glass substrates or maskblanks in the cassette are arranged while being aligned in the samedirection, so as to be placed.

In this embodiment, the glass substrates or mask blanks are placed sothat the notch marks 1 of the glass substrates are located at specificpositions on the front side of the distribution cassette 2.

That is, the glass substrates or mask blanks are placed such that, usingthe front of the distribution cassette 2 as a reference, the substratesurfaces formed with the notch marks 1 are arrayed so as to face thecassette front and, further, the notch marks of the glass substrates arealigned in the same positional relationship as seen from the cassettefront.

In the subsequent processes, distribution cassettes that carrysubstrates between the respective processes have the same structure asthat of the foregoing distribution cassette 2.

(2) First Film Forming Process

By the use of a host computer that carries out production management,the ID tag 2′ attached to the distribution cassette 2 is assignedmanagement numbers serving to manage the respective substrates. The hostcomputer correlates the management numbers assigned to the ID tag withmanufacturing process order in which the respective substrates should beprocessed and manufacturing conditions to be used in the respectiveprocesses. The host computer has the function of collecting information(e.g. substrate information, film information, etc.) from respectiveapparatuses in the manufacturing processes and recording/storing it permanagement number.

Specifically, the host computer that carries out production managementassigns the management numbers, for managing the distribution cassetteor the respective placed substrates, to the ID tag 2′ attached perdistribution cassette and records them. Further, the host computercorrelates the management numbers assigned to the ID tag 2′ with orderof the plurality of manufacturing processes and inspection processeswhere the respective substrates are processed, the manufacturingconditions to be set in those processes, and so on. Further, the hostcomputer has the function of collecting, recording, and storing, persubstrate, information of the respective processes (e.g. substrateinformation, film information produced in the inspection processes ofrespective thin films, manufacturing conditions and manufacturingrecipes used in the forming processes of respective thin films, and soon) acquired in the plurality of processes.

The glass substrates placed in the distribution cassette 2 are taken outone by one. The substrate is disposed on a holder of a sputteringapparatus so that the substrate surface on the side where the notchmarks 1 are formed faces upward, while, the substrate surface on theside where the notch marks are not formed faces a sputtering target.

Then, by the use of a MoSi sputtering target, a halftone film being aphase shift film is formed on the surface of the glass substrate in amixed gas atmosphere of argon gas and nitrogen gas by a reactivesputtering method.

The film is formed on the main surface of the glass substrate opposite(opposing surface) to the main surface where the notch marks 1 areformed. In the manner as described above, the phase shift film being thehalftone film containing MoSiN is formed on the surface of the glasssubstrate.

The substrate holder is provided with shielding means so that the MoSiNhalftone film is not formed in predetermined regions at the peripheralportion of the main surface of the substrate.

By this shielding means, the predetermined regions where the MoSiN filmis not formed are formed on the main surface of the substrate and serveas film marks 3.

By the use of the difference in shape of the film mark 3, the positionof the film mark, the arrangement thereof, or the like, it is possibleto distinguish the kind of thin film formed on the glass substrate. Inthis embodiment, use is made of a film mark that is used for a halftonefilm.

Like the foregoing notch mark 1, the film mark 3 can be used as areference mark for specifying the directivity of the substrate and as areference point in film information acquired in the later-describedinspection process.

As a specific example, film marks 31 can be provided at two corners onthe main surface on the side opposite to the side where the notch marks1 are formed, as shown in FIG. 16B.

The MoSiN halftone film coated substrates each formed with the MoSiNfilm on the surface of the glass substrate by the sputtering apparatusare placed in a distribution cassette 4 different from the distributioncassette 2. In the distribution cassette 4, the plurality of halftonefilm coated substrates are placed with their directions aligned on thebasis of the notch marks 1 or the film marks 3.

Specifically, the substrates are placed so that the film marks 3 formedon the substrates are arranged in a predetermined relationship to apredetermined position of the distribution cassette 4.

In this embodiment, the plurality of halftone film coated substrates areplaced so that the film marks 3 of the substrates are located atspecific positions (on the lower side with respect to the distributioncassette in FIG. 15) on the back side of the distribution cassette 4.

That is, the substrates are placed such that, using the front of thedistribution cassette 4 as a reference, the substrate surfaces on theside where the film marks 3 are not formed are arrayed so as to face thecassette front, i.e. the substrate surfaces formed with the notch marks1 are arrayed so as to face the cassette front and, further, the filmmarks 3 of the substrates are aligned in the same positionalrelationship (on the lower side with respect to the distributioncassette in FIG. 15) as seen from the cassette front.

Information of the completion of the first film formation is stored permanagement number in the host computer.

Further, the information of the management numbers assigned to the IDtag 2′ is transferred to an ID tag 4′ attached to the distributioncassette 4. The management numbers transferred to the ID tag 4′ may bethe same as the management numbers assigned to the ID tag 2′ or newmanagement numbers may be assigned from the host computer. In the lattercase, the management numbers newly assigned to the ID tag 4′ are storedin the host computer while being correlated with the management numbersassigned to the ID tag 2′.

(3) First Film Inspection Process

This process includes a process of acquiring thin film information ofthe first film and a thin film information recording process ofrecording and storing the acquired film information in an informationstorage medium.

The halftone film coated substrate placed in the distribution cassette 4is taken out and placed on a defect inspection apparatus that inspects adefect of the first film (MoSiN halftone film).

The substrate is placed on a holder while the surface formed with thenotch marks 1 faces downward and the surface formed with the film marks3 faces upward.

Thereafter, the surface of the film is scanned using the first-filmdefect inspection apparatus, thereby acquiring film information aboutthe first film.

The film information is state information relating to the state of thefilm and surface information of the film acquired by scanning thesurface of the film. As the film information, surface form informationand optical property information can be cited. The acquired filminformation is configured such that it can be comprehended astwo-dimensional plane information by projecting it onto the plane.

Position information (e.g. X and Y coordinates in the plane coordinatesystem) of a defect that may cause pattern failure in the maskmanufacturing process, the size of the defect, the type of the defect,and so on are judged per defect by the defect inspection apparatus andits results are stored per management number in the host computer.

In this event, as the size of the defect, a measured value indicatingthe size of the defect such as a diameter may be stored as it is, or, aplurality of ranks for classifying the defect sizes may be determined inadvance and the relevant rank may be stored as the size of the defect.

The type of the defect may be classified as a convex shape, a concaveshape, or the other defect and stored. As the convex shape, there is,for example, a pinhole-shaped defect, while, as the concave shape, thereis cited, for example, a particle-shaped defect.

The particle-shaped defect represents a defect in the state whereforeign matter (e.g. granular or the like) is adhered on the film or inthe film, while, the pinhole-shaped defect represents a trace whereforeign matter once adhered in the film has fallen off, i.e. a defect ina film fall-off state. The film fall-off represents a state with no filmat all where the state of an underlayer of the film can be confirmed ora state with a locally thinned film thickness where the state of anunderlayer of the film cannot be confirmed.

The position information is stored as X and Y coordinates of each defectin an XY coordinate system formed by calculating, as a reference point(O), the center of the main surface of the glass substrate from the sizeof the glass substrate on the basis of the notch mark 1 and using, asvirtual X and Y axes, lines passing through the reference point andparallel to sides of the glass substrate.

Specifically, at first, the center of the main surface of the glasssubstrate is calculated, as a reference point (O), from the size of theglass substrate, for example, the lengths of sides thereof, on the basisof the position of the notch mark 1, then, using the reference point (O)as the origin, an orthogonal plane coordinate system (XY coordinatesystem) is defined along the orthogonal sides of the glass substrate,and finally, an X-coordinate position and a Y-coordinate position ofeach defect is calculated in the two-dimensional XY coordinate system,thereby storing the foregoing defect position information in terms ofvalues of the calculated X and Y coordinates.

The film information of the thin film acquired here is called first-filmfilm information.

The halftone film coated substrates having been subjected to the defectinspection are placed in a distribution cassette 5 different from thedistribution cassette 4. In the distribution cassette 5, the pluralityof halftone film coated substrates are placed with their directionsaligned on the basis of the notch marks 1 or the film marks 3.

Specifically, the substrates are placed so that the film marks 3 formedon the substrates are arranged in a predetermined relationship to apredetermined position of the distribution cassette 5.

In this embodiment, the plurality of halftone film coated substrates areplaced so that the film marks 3 of the substrates are located atspecific positions (on the lower side with respect to the distributioncassette in FIG. 15) on the back side of the distribution cassette 5.

That is, the substrates are placed such that, using the front of thedistribution cassette 5 as a reference, the substrate surfaces formedwith the notch marks are arrayed so as to face the cassette front,while, the surfaces formed with the film marks 3 are arrayed so as toface the side opposite to the cassette front, and further, the filmmarks 3 of the substrates are aligned in the same positionalrelationship (on the lower side with respect to the distributioncassette in FIG. 15) as seen from the cassette front.

Since the placement method is managed before the inspection so that theplacing directions of the plurality of substrates are aligned aspredetermined, the directivity, the coordinate system, and the referencepoint of the plane information acquired in the inspection process arecoordinated among the plurality of substrates, thereby acquiring theinformation.

Since the placement method is managed after the inspection so that theplacing directions of the plurality of substrates are aligned aspredetermined, the directivity (direction) of the substrates subjectedto processing is maintained also in the next process.

Along with this, the information of the management numbers assigned tothe ID tag 4′ is transferred to an ID tag 5′ of the distributioncassette 5. As described above, the management numbers transferred tothe ID tag 5′ may be the same as the management numbers assigned to theID tag 4′ or new management numbers may be assigned.

The substrates placed in the cassette are transferred to the nextprocess per cassette.

(4) Second Film Forming Process

Then, the halftone film coated substrate placed in the distributioncassette 5 is placed on a holder of an in-line sputtering apparatus. Inthis event, the substrate is placed on the holder while the substratesurface on the side formed with the notch marks 1 faces upward and thesurface on the side formed with the film marks 3 faces downward.

By the use of a chromium (Cr) sputtering target, a light shielding filmcontaining Cr (hereinafter referred to as the Cr light shielding film)being a second film is formed on the MoSiN halftone film being the firstfilm in an argon gas atmosphere or in a mixed gas atmosphere of argongas and oxygen gas and/or nitrogen gas by a reactive sputtering method.

In order to prevent formation of the Cr light shielding film inpredetermined regions at the peripheral portion of the main surface ofthe substrate, the substrate holder is provided with shielding means.Accordingly, the predetermined regions where the Cr light shielding filmis not formed are formed on the MoSiN halftone film so that film marks 6are provided. By the shape of the film mark 6, the kind of film can bedistinguished. In this embodiment, use is made of a film mark adaptedfor a Cr light shielding film.

Like the notch mark 1 formed on the glass substrate or the film mark 3formed at the halftone film, the film mark 6 formed at the Cr lightshielding film can be used as a reference mark for specifying thedirectivity of the substrate and as a reference point in filminformation acquired in the later-described defect inspection process.

In this embodiment, the MoSiN halftone film is covered with the Cr lightshielding film. Therefore, it is difficult to see the film marks 3 fromthe side of the substrate where the films are formed. However, the filmmarks 3 given to the halftone film can be confirmed through the glasssubstrate from the main surface of the substrate on the opposite side.When specifying the directivity of the substrate by the use of the filmmarks 3, they can be utilized from the side of the substrate where thefilms are not formed.

The substrates each having the Cr light shielding film formed on theMoSiN halftone film by the in-line sputtering apparatus are placed in adistribution cassette 7 different from the distribution cassette 5. Inthe distribution cassette 7, the plurality of Cr light shielding filmcoated substrates are placed with their directions aligned on the basisof the film marks 6.

Specifically, the substrates are placed so that the film marks 6 formedon the substrates are arranged in a predetermined relationship to apredetermined position of the distribution cassette 7.

In this embodiment, the plurality of Cr light shielding film coatedsubstrates are placed so that the film marks 6 of the substrates arelocated at specific positions (on the upper side with respect to thedistribution cassette in FIG. 15) on the back side of the distributioncassette 7.

That is, the substrates are arrayed such that, using the front of thedistribution cassette 7 as a reference, the surfaces on the side formedwith the film marks 6 face the side opposite to the cassette front andthe surfaces on the side formed with the notch marks 1 face the cassettefront side. The substrates are placed so that the film marks 6 of thesubstrates are aligned in the same positional relationship (on the upperside with respect to the distribution cassette in FIG. 15) as seen fromthe cassette front.

Information of the completion of the second film formation is stored permanagement number in the host computer. The information of themanagement numbers assigned to the ID tag 5′ is transferred to an ID tag7′ attached to the distribution cassette 7. As described above, themanagement numbers transferred to the ID tag 7′ may be the same as themanagement numbers assigned to the ID tag 5′ or new management numbersmay be assigned.

The film coated substrates each having the first film and the secondfilm stacked on the substrate are placed in the cassette 7 andtransferred to the next process.

(5) Second Film Inspection Process

This process is similar to the first film inspection process. Thisprocess includes a process of acquiring thin film information of thesecond film and a thin film information recording process of recordingand storing the acquired film information in an information storagemedium.

The Cr light shielding film coated substrate placed in the distributioncassette 7 is set on a substrate placement stage of an inspectionapparatus that inspects a defect of the second film (Cr light shieldingfilm). In this event, the substrate is disposed while the surface formedwith the notch marks 1 faces downward, the surface formed with the filmmarks 6 faces upward, and the notch marks 1 are located at predeterminedpositions with respect to the placement stage.

Like in the foregoing defect inspection of the first film, a defectinspection of the second film is carried out to acquire film informationof the second film. The surface of the film is scanned using thesecond-film defect inspection apparatus, thereby acquiring the filminformation about the second film.

The film information is state information relating to the state of thefilm and surface information of the film acquired by scanning thesurface of the film. As the film information, surface form informationand optical property information can be cited. The acquired filminformation is configured such that it can be comprehended astwo-dimensional plane information by projecting it onto the plane.

Position information (e.g. X and Y coordinates in the plane coordinatesystem) of a defect that may cause pattern failure in the maskmanufacturing process, the size of the defect, the type of the defect,and so on are judged by the defect inspection apparatus and its resultsare stored per management number in the host computer.

The sizes of defects can be individually stored, but, for example, maybe indicated by predetermined size ranks.

The type of the defect may be classified as a convex shape, a concaveshape, or the other defect and stored. As the convex shape, there is,for example, a pinhole-shaped defect, while, as the concave shape, thereis cited, for example, a particle-shaped defect.

The particle-shaped defect represents a defect in the state whereforeign matter (e.g. granular or the like) is adhered on the film or inthe film, while, the pinhole-shaped defect represents a trace whereforeign matter once adhered in the film has fallen off, i.e. a defect ina film fall-off state. The film fall-off represents a state with no filmat all where the state of an underlayer of the film can be confirmed ora state with a locally thinned film thickness where the state of anunderlayer of the film cannot be confirmed.

The position information is stored as X and Y coordinates of each defectin an XY coordinate system formed by calculating, as a reference point(O), the center of the main surface of the glass substrate from the sizeof the glass substrate on the basis of the notch mark 1 and using, asvirtual X and Y axes, lines passing through the reference point andparallel to sides of the glass substrate.

Like in the first film inspection process, at first, the center of themain surface of the glass substrate is calculated, as a reference point(O), from the size of the glass substrate, for example, the lengths ofsides thereof, on the basis of the position of the notch mark 1, then,using the reference point (O) as the origin, an orthogonal planecoordinate system (XY coordinate system) is defined along the orthogonalsides of the glass substrate, and finally, an X-coordinate position anda Y-coordinate position of each defect is calculated in thetwo-dimensional XY coordinate system, thereby storing the foregoingdefect position information in terms of values of the calculated X and Ycoordinates. The film information acquired here is called second-filmfilm information.

The Cr light shielding film coated substrates having been subjected tothe defect inspection are placed in a distribution cassette 8 differentfrom the distribution cassette 7. In the distribution cassette 8, theplurality of Cr light shielding film coated substrates are placed withtheir directions aligned on the basis of the film marks 6.

Specifically, the substrates are placed so that the film marks 6 formedon the substrates are arranged in a predetermined relationship to apredetermined position of the distribution cassette 8.

In this embodiment, the plurality of Cr light shielding film coatedsubstrates are placed so that the film marks 6 of the substrates arelocated at specific positions (on the upper side with respect to thedistribution cassette in FIG. 15) on the back side of the distributioncassette 8.

That is, using the cassette front of the distribution cassette 8 as areference, the surfaces formed with the film marks 6 are arrayed so asto face the side opposite to the cassette front, i.e. the surfacesformed with the notch marks 1 are arrayed so as to face the cassettefront. Further, the substrates are placed so that the film marks 6 ofthe substrates are aligned in the same positional relationship (on theupper side with respect to the distribution cassette in FIG. 15) as seenfrom the cassette front.

Since the placement method is managed before the inspection so that theplacing directions of the plurality of substrates are aligned aspredetermined, the directivity, the coordinate system, and the referencepoint of the plane information acquired in the inspection process arecoordinated among the plurality of substrates, thereby acquiring theinformation.

Since the placement method is managed after the inspection so that theplacing directions of the plurality of substrates are aligned aspredetermined, the directivity (direction) of the substrates subjectedto processing is maintained also in the next process.

The information of the management numbers assigned to the ID tag 7′ istransferred to an ID tag 8′ attached to the distribution cassette 8. Asdescribed above, the management numbers transferred to the ID tag 8′ maybe the same as the management numbers assigned to the ID tag 7′ or newmanagement numbers may be assigned.

The substrates placed in the cassette are transferred to the nextprocess per cassette.

(6) Resist Film Forming Process

The Cr light shielding film coated substrate placed in the distributioncassette 8 is transferred into a spin coating apparatus where a resistfilm is coated on the second film by a spin coating method, therebyforming the resist film through baking and cooling.

In the manner as described above, a mask blank is fabricated in whichthe substrate, the first film, the second film, and the resist film arestacked together. There is a case where the resist film is not formed ifnecessary.

The fabricated mask blanks are placed in a distribution cassette 9different from the distribution cassette 8. In the distribution cassette9, the plurality of mask blanks are placed with their directions alignedon the basis of the film marks 6.

Specifically, the mask blanks are placed so that the film marks 6 formedon the substrates are arranged in a predetermined relationship to apredetermined position of the distribution cassette 9.

In this embodiment, the plurality of mask blanks are placed so that thefilm marks 6 of the mask blanks are located at specific positions (onthe upper side with respect to the distribution cassette in FIG. 15) onthe back side of the distribution cassette 9.

That is, the mask blanks are placed such that, using the cassette frontof the distribution cassette 9 as a reference, the surfaces formed withthe film marks 6 are arrayed so as to face the side opposite to thecassette front, i.e. the surfaces formed with the notch marks 1 arearrayed so as to face the cassette front, and further, the film marks 6of the substrates are aligned in the same positional relationship (onthe upper side with respect to the distribution cassette in FIG. 15) asseen from the cassette front.

Information of the completion of the resist film formation is stored persubstrate number in the host computer. The information of the managementnumbers assigned to the ID tag 8′ is transferred to an ID tag 9′attached to the distribution cassette 9. As described above, themanagement numbers transferred to the ID tag 9′ may be the same as themanagement numbers assigned to the ID tag 8′ or new management numbersmay be assigned.

(7) Resist Film Inspection Process

This process is similar to the first film inspection process or thesecond film inspection process. This process includes a process ofacquiring thin film information of the resist film and a thin filminformation recording process of recording and storing the acquired filminformation in an information storage medium.

The resist film coated substrate (mask blank) placed in the distributioncassette 9 is set on a substrate placement stage of a defect inspectionapparatus that inspects a defect of the resist film.

In this event, the mask blank is placed on the stage while the surfaceformed with the notch marks 1 faces downward and the surface formed withthe film marks 6 faces upward. Further, the mask blank is set so thatthe notch marks 1 are located at predetermined positions with respect tothe stage.

A defect inspection of the resist film is carried out to acquire filminformation of the resist film. The surface of the film is scanned usingthe resist-film defect inspection apparatus, thereby acquiring the filminformation about the resist film.

The film information is state information relating to the state of thefilm and surface information of the film acquired by scanning thesurface of the film.

As the film information, surface form information and optical propertyinformation can be cited. The acquired film information is configuredsuch that it can be comprehended as two-dimensional plane information byprojecting it onto the plane.

Position information (e.g. X and Y coordinates in the plane coordinatesystem) of a defect that may cause pattern failure in the maskmanufacturing process, the size of the defect, the type of the defect,and so on are judged by the defect inspection apparatus and its resultsare stored per management number in the host computer.

The position information is stored as X and Y coordinates of each defectin an XY coordinate system formed by calculating, as a reference point(O), the center of the main surface of the glass substrate from the sizeof the glass substrate on the basis of the notch mark 1 and using, asvirtual X and Y axes, lines passing through the reference point andparallel to sides of the glass substrate.

Like in the foregoing first film inspection process and second filminspection process, at first, the center of the main surface of theglass substrate is calculated, as a reference point (O), from the size(lengths of sides) of the glass substrate on the basis of the positionof the notch mark 1, then, using the reference point (O) as the origin,an orthogonal coordinate system (XY coordinate system) is defined alongthe orthogonal sides of the glass substrate, and finally, anX-coordinate position and a Y-coordinate position of each defect iscalculated in the XY coordinate system, thereby storing the foregoingdefect position information in terms of values of the calculated X and Ycoordinates. The film information acquired here is called resist-filmfilm information.

The mask blanks having been subjected to the defect inspection areplaced in a distribution cassette 10 different from the distributioncassette 9. In the distribution cassette 10, the plurality of maskblanks are placed with their directions aligned on the basis of the filmmarks 6.

Specifically, the mask blanks are placed so that the film marks 6 formedon the substrates are arranged in a predetermined relationship to apredetermined position of the distribution cassette 10.

In this embodiment, the plurality of mask blanks are placed so that thefilm marks 6 of the mask blanks are located at specific positions (onthe upper side with respect to the distribution cassette in FIG. 15) onthe back side of the distribution cassette 10. That is, the mask blanksare placed such that, using the cassette front of the distributioncassette 10 as a reference, the surfaces formed with the film marks 6are arrayed so as to face in a direction opposite to the cassette front,i.e. the surfaces formed with the notch marks 1 are arrayed so as toface the cassette front, and further, the film marks 6 of the substratesare aligned in the same positional relationship (on the upper side withrespect to the distribution cassette in FIG. 15) as seen from thecassette front.

Since the placement method is managed before the inspection so that theplacing directions of the plurality of mask blanks are aligned aspredetermined, the directivity, the coordinate system, and the referencepoint of the plane information acquired in the inspection process arecoordinated among the plurality of mask blanks, thereby acquiring theinformation.

Since the placement method is managed after the inspection so that theplacing directions of the plurality of mask blanks are aligned aspredetermined, the directivity (direction) of the mask blanks ismaintained also in the next process.

The information of the management numbers assigned to the ID tag 9′ istransferred to an ID tag 10′ attached to the distribution cassette 10.As described above, the management numbers transferred to the ID tag 10′may be the same as the management numbers assigned to the ID tag 9′ ornew management numbers may be assigned.

(8) Film Information Collation Process

The film information acquired with respect to the respective thin films,i.e. the first film, the second film, and the resist film, formed inorder on the glass substrate are collated with each other. When thesubstrate information has been acquired, the substrate information andthe film information can be collated.

The film information relating to the mask blank to be collated can beidentified by the management number.

In this invention, the film information is acquired as the planeinformation. The reference point of position in the plane information isacquired so as to have the predetermined relationship to the notch markor the film mark provided on the substrate or the mask blank so as toserve as the reference mark. Further, when acquiring the filminformation or the plane information, the information is acquired whilethe substrates or the mask blanks are all aligned in the same direction.

By collating the first-film film information, the second-film filminformation, and the resist-film film information with each other, it ispossible to verify whether the respective film information are surfaceinformation with the consistent direction. Further, based on theverification results, the directions of the respective film informationcan be made consistent with each other.

Specifically, the film information of the respective films can becollated on the basis of a shape that does not change in position, i.e.is located at the same position, on the substrate before and after thefilm forming process.

For example, when a specific shape such as a defect exists in the firstfilm being a film at the lowermost layer, the shape of the first film isreflected also on the second film and the resist film being films atlayers above the first film and hence it is possible to confirm bycollation on the basis of the first-film film information whether thedirectivities of the other film information, i.e. the reference pointsor the XY coordinate systems in the position information, coincide witheach other.

For example, when a defect exists in the first film being a film at thelowermost layer, defects also occur in the second film and the resistfilm being films at layers above the first film and hence it is possibleto judge based on the defect included in the first-film film informationwhether or not the directions of the other film information are correct.

FIG. 17 shows an example where first-film film information, second-filmfilm information, and resist-film film information are collated. In FIG.17, the collation is carried out on the basis of defects commonlydetected in the first-film film information, the second-film filminformation, and the resist-film film information. Specifically, it isthe example where the film information of the second film and the resistfilm are collated on the basis of defects (portion where □, Δ, and xoverlap each other) that do not change in position coordinates on thesubstrate and thus are located at the same position.

By carrying out the collation of the film information as describedabove, the directivities (directions) of the respective filminformation, i.e. the reference points and the XY coordinate systems inthe position information, can be made consistent with each other.

On the other hand, for example, the possibility is considered that whenmoving a substrate from a certain distribution cassette to anotherdistribution cassette, the substrate may be placed in the distributioncassette with its directivity being wrong. Further, the possibility isconsidered that when moving a substrate from a distribution cassette toeach inspection apparatus or from each inspection apparatus to adistribution cassette, the substrate may be placed or removed with itsdirectivity being wrong. In this case, there is a possibility that thedirections of the film information and the mask blank disagree.

In order to avoid such a possibility, when placing or removing asubstrate or a mask blank in or from a distribution cassette or areceiving case or when setting a substrate in the defect inspectionapparatus for each film, an operator refers to a notch mark 1 or a filmmark 3 or 6 as a reference mark indicating the direction of thesubstrate and places or removes the substrate or the mask blankaccording to a predetermined directivity (direction).

Specifically, as described before, with respect to a distributioncassette that carries substrates or mask blanks between the respectiveprocesses, the substrates or the mask blanks may be placed such thatnotch marks of the substrates or the mask blanks are arrayed so as toface the front side of the distribution cassette and the notch marks arealigned at the predetermined position.

The description has been made about the case where the front indicationof the cassette is given for convenience' sake. However, for example, ifthe direction of a cassette is always ensured to be the same direction,the visible front indication is not necessarily required. Further, ifthe direction of a cassette is seized and managed by the host computeror the like, the visible front indication is not necessarily required.

Substrates or mask blanks are placed while film marks 3 are arranged atthe lower position in a distribution cassette and film marks 6 arearranged at the upper position in the distribution cassette.

Further, when setting a substrate or a mask blank in the defectinspection apparatus for each film, the substrate or the mask blank maybe placed on the stage so that notch marks or film marks face in thepredetermined direction and further the notch marks or the film marksare located at the predetermined positions with respect to the stage,thereby carrying out the predetermined inspection.

By this, it is possible to prevent in advance occurrence ofinconsistency in directivity (direction) among film information.Further, it is possible to prevent in advance occurrence ofinconsistency between the directivity (direction) of the filminformation and the directivity (direction) of the placed mask blank.

By keeping constant the directivity (direction) of the substrate or themask blank during the manufacture of the mask blank, the reference pointand the XY coordinate system of the mask blank can be made consistentand, further, the reference point and the XY coordinate system of themask blank can be made consistent with the reference point and the XYcoordinate system of the film information of each film.

As described above, since the mask blank information is configured suchthat the plane coordinates and the position reference points of theposition information included in the film information and the substrateinformation can be correlated with each other, the mask blankinformation can be recognized as internal three-dimensional informationinside the mask blank body.

Further, since the mask blank information has been subjected to theforegoing collation process, it can be guaranteed as highly reliablethree-dimensional information inside the mask blank body.

(9) Mask Blank Packaging Process

The mask blanks are placed in a receiving case 20 and packaged, and thendelivered to a mask maker.

Herein, the receiving case 20 will be described with reference to FIGS.18A and 18B. A unique case number 21 is assigned and attached to each ofreceiving cases 20.

This case number 21, along with later-described slot numbers, areassigned while being correlated with the managing numbers assigned forcorrelation between the respective substrates and the information (e.g.film information) of the respective processes in the foregoingmanufacture of the mask blanks. Further, the case number 21 iscorrelated with the film information of the respective films or thesubstrate information stored in the host computer.

Although the case number 21 is attached to the receiving case 20, theattachment of the case number 21 is not limited to a visible state suchas printing and it may be attached as a readable medium such as, forexample, a barcode, a magnetic recording medium, an IC chip, or an ICtag.

The receiving case 20 comprises a lid 22 and an outer box 23, wherein aninner box 24 is further received in the outer box 23. In the inner box24, a plurality of slots 25 being partitions are formed from upper tolower and a plurality of grooves are formed at predetermined intervalsbetween the slots 25 so that mask blanks can be received in thesegrooves.

Although the slot 25 is a partition between the mask blanks, a grooveportion between the adjacent two slots 25 for storing the substrate willalso be called a slot hereinbelow for the sake of explanation. In thissense, there are five grooves, i.e. five slots, for storing fivesubstrates in FIG. 18B.

Slot numbers are assigned corresponding to the grooves, which are calledslot No. 1, slot No. 2, . . . slot No. 5, respectively. Among outersurfaces of the outer box 23, a front indication 26 showing thedirection of the receiving case 20 is described on the surface close toslot No. 1.

The mask blanks are placed in the respective grooves (slot No. 1, slotNo. 2, . . . slot No. 5) while the notch marks 1 formed on the maskblanks are arranged at specific positions on the side of the frontindication 26 and, further, the film marks 3 are arranged on the lowerside with respect to the receiving case and the film marks 6 arearranged on the upper side with respect to the receiving case, so as tobe packaged.

By the combination of the foregoing case number and slot numbers, it ispossible to identify the mask blank individuals stored in the receivingcase 20. By the case number and the slot number, the film information ofthe respective films or the substrate information stored in the hostcomputer is correlated so that the mask blank information is specified.

As described above, also in the packaging process, by placing the maskblanks in the respective grooves while the notch marks 1 formed on themask blanks are arranged at the specific positions on the side of thefront indication 26, the film marks 3 are arranged on the lower sidewith respect to the receiving case, and the film marks 6 are arranged onthe upper side with respect to the receiving case, the reference pointand the XY coordinate system of each mask blank and the reference pointand the XY coordinate system of the film information of each film or thesubstrate information can be made consistent with each other.

Accordingly, the mask blank individual and the mask blank informationrelating to such a mask blank individual can be accurately correlatedwith each other, so that it is possible to prevent pattern failure inthe mask fabrication.

Further, a mask fabricator can comprehend not only the surfaceinformation of the mask blank, but also the internal state of the maskblank.

Next, referring to FIG. 19, description will be made about a mask blankproviding method of providing to a mask maker the mask blanks stored inthe receiving case finished with the blank packaging process and thefilm information of those mask blanks, and a mask fabrication supportingsystem.

As described above, the mask blank individual information (mask blankinformation) including the first-film film information, the second-filmfilm information, and the resist-film film information stored permanagement number in the host computer is provided to the mask makeralong with the mask blanks stored in the receiving case, while beingcorrelated with the mask blank individuals identified by the case numberand the slot numbers.

As mask blank film information providing methods, there are (a)attaching a print printed with the information to the receiving case 20,(b) attaching to the receiving case 20 a recording medium such as aflexible disk or a CD-ROM recording the information data, (c)transmitting the information data to a computer or the like of the maskmaker at the delivery destination through a data communication line, andso on.

In the case of (a) or (b), the information itself is attached to thereceiving case 20 along with a correlation with slot numbers. In thecase of (c), the mask maker transmits a case number and a slot numberand receives the corresponding information.

The information may be mapped as shown in FIG. 17 so that it can bevisually seen how respective defects are arranged or may be in the formof a data sheet about the type of each defect, the size of each defect,and position information (X coordinate, Y coordinate) of each defect.Although the information is generally provided to the mask maker as thefilm information of each film, the film information of the respectivefilms may be provided to the mask maker as a single defect map as shownin FIG. 17.

As described above, in this embodiment, the position information, forexample, the defect position information, in the substrate informationor the film information acquired as the plane information is given by Xand Y coordinates of each defect in the XY coordinate system formed bycalculating, as a reference point (O), the center of the main surface ofthe substrate on the basis of the notch mark 1 and passing through thisreference point and, further, the mask blanks stored in the receivingcase are placed so that the notch marks 1 are located at the specificpositions with respect to the receiving case. Therefore, the informationand the mask blanks are provided to the mask maker in the state wherethe reference point and the coordinate system in each of the mask blanksstored in the receiving case and the reference point and the coordinatesystem in the position information can be comprehended in terms of theircorrelation or are made consistent with each other.

As described above, the mask blank information corresponding to therespective mask blank individuals is provided to the mask maker. Themask blank individuals to be provided are each provided to the maskmaker in the state where its position reference point and coordinatesystem correspond to the position reference point and the coordinatesystem of the blank film information.

The mask maker utilizes the means such as the case number and the slotnumber, or the management number or management symbol indirectlyassigned to each of the mask blanks for specifying it to therebyidentify each of the provided mask blank individuals and, through thereference points and the coordinate systems in the foregoingpredetermined relationship, can perform collation between each of theprovided mask blanks and the mask blank information. Further, throughthe reference points and the coordinate systems in the foregoingpredetermined relationship, it is possible to accurately comprehend thestates such as the surface forms of the individual mask blanks.

Therefore, a region on each mask blank where a predetermined transferpattern (mask pattern) is to be formed can be properly specified asrequired. Thus, it is possible to suppress pattern formation failure ofthe pattern to be formed.

The mask maker can specify a region on each mask blank where a maskpattern including a transfer pattern is to be formed and pattern a thinfilm formed on the mask blank, thereby fabricating a transfer mask.

Next, using as a specific example the foregoing providing method (c) ofproviding the information through the data communication line, a maskfabrication supporting system 110 of this invention will be describedwith reference to FIG. 19.

Referring to FIG. 19, the mask fabrication supporting system 110comprises a mask blank factory 111, a mask factory 112 that manufacturesmasks based on mask blanks manufactured in the mask blank factory 111,and a data communication line 113 connecting both factories together.Further, the mask blank factory 111 comprises a host computer 51 and aserver 114.

The mask blanks manufactured in the mask blank factory 111 are deliveredto the mask factory 112 while being placed in the foregoing receivingcase 10. The host computer 51 is the foregoing host computer 51 of themask blank production line control system 50.

The server 114 receives necessary information (film information etc.)from the host computer 51. In the server 114, case numbers and slotnumbers adapted to identify the mask blanks delivered to the maskfactory 112 and the blank film information are stored while beingcorrelated with each other. The server 114 provides the predeterminedinformation to a computer of the mask factory 112 at a remote placethrough the Internet 113.

The case numbers and the slot numbers adapted to identify the maskblanks delivered to the mask factory 112 and the mask blank informationsuch as the film information may be stored in the host computer 51 whilebeing correlated with each other.

Next, referring to FIG. 20, description will be made about one exampleof the mask manufacturing process including a process carried out by themask factory 112 for writing/developing a pattern on a resist film ofeach mask blank by the use of the information received in the maskfabrication supporting system 110.

An operator, in receipt of a receiving case 10, in the mask factory 112acquires a case number from the receiving case 10 visually or bymechanical reading and then, by the use of a data communicationapparatus such as a computer, transmits the case number to the server114 through the data communication line 113 such as the Internet. Inresponse thereto, the server 114 transmits film information of maskblanks placed in respective slots of the receiving case of that casenumber, while correlating the film information with the case number andslot numbers (step S121).

Various manners can be considered as manners of data communication. Forexample, transmission of both information such as a case number and slotnumbers for identifying mask blank individuals and mask blankinformation such as film information may be carried out throughelectronic mails.

Alternatively, a database representing a correlation between casenumbers and information of mask blanks placed in respective grooves ofreceiving cases of those case numbers may be installed on the server 114and the mask blank information such as the film informationcorresponding to the case number input from the side of the mask factory112 may be transmitted in reply.

At this stage, each mask blank has a section shown in FIG. 21A, whereinfilms of a plurality of layers, i.e. a first film (halftone film), asecond film (light shielding film), and a resist film, are stacked on aglass substrate.

The mask factory 112 in receipt of the film information collates betweenthe acquired film information and mask pattern data of a mask to bemanufactured (step S122).

As described above, in this event, a reference point and an XYcoordinate system of the mask blank and a reference point and an XYcoordinate system of position information in the film informationcorrespond to each other. Therefore, by the collation between the filminformation and the mask pattern data, it is possible to determine thearrangement of a mask pattern with respect to the mask blank.

Now, it is assumed that the mask factory 112 is in receipt of mask blankinformation 141 from the mask blank factory 111 and is going to write amask pattern 142. The mask blank information 141 includes first-filmfilm information, second-film film information, and resist-film filminformation.

Generally, as shown in FIG. 22, a mask pattern formed on a mask has adense pattern region 143 where the density of a pattern is high and asparse pattern region 144 where the density of a pattern is low.

As the mask having the region 143 where a dense pattern is formed as amask pattern and the region 144 where a sparse pattern is formed, thereis cited a system LSI manufacturing mask or the like.

Particularly, the mask fabrication supporting method of this inventionis particularly effective to the case of a pattern having, as a sparsepattern forming region, a monitor chip forming region formed for testingelectrical properties.

On the other hand, generally, defects of a mask blank that may causepattern failure in the mask manufacturing process, specifically,pinholes and particles, are often not uniformly distributed but unevenlydistributed.

Referring to the received film information 141 being the mask blankinformation, the pattern writing position is determined throughadjustment so that pinholes and particles which may cause patternfailure are located in the region other than the dense pattern formingregion 143 in the mask pattern data (step S123).

As a pattern writing position adjusting method, it is considered tochange the direction of the mask pattern 142 with respect to thedirection of the mask blank. On the other hand, if it is possible tochange the relative position relationship between the dense patternforming region 143 and the sparse pattern forming region 144, theadjustment may be carried out by changing it.

Finally, in accordance with the determined pattern writing position, apattern is written on the resist film and developed, thereby obtaining amask formed with a mask pattern (transfer pattern) on the glasssubstrate (step S124).

In the mask fabricated through the foregoing steps S121 to S124,pinholes and particles in the mask blank that may cause pattern failureare located in the sparse pattern forming region and hence it ispossible to suppress pattern formation failure of the mask pattern.

Next, referring to FIG. 23, description will be made in detail about oneexample of a mask blank production line control system 50 wherein thehost computer 51 collects information of the respective processes (e.g.substrate information and film information produced in the respectiveinspection processes and information such as manufacturing conditionsand recipes) from the respective apparatuses in the foregoingembodiment.

Referring to FIG. 23, the mask blank production control system 50comprises a host computer 51, a cassette number/slot number assigner 52(hereinafter referred to as the assigner 52), a first film formingapparatus 53, a first film defect inspection apparatus 54, a second filmforming apparatus 55, a second film defect inspection apparatus 56, aresist film forming apparatus 57, and a resist film defect inspectionapparatus 58.

A distribution cassette has a plurality of grooves formed atpredetermined intervals and extending from upper to lower so as toreceive a plurality of substrates therein and is provided with an IDtag. The ID tag is assigned information adapted to manage the respectivesubstrates placed in the distribution cassette. Specifically, a cassettenumber of the distribution cassette is recorded.

Referring to FIG. 24, when putting substrates on the production line,the substrates are placed in respective grooves of a distributioncassette and a cassette number, slot numbers, and a process flow areinput into an ID tag from an input section 521 in the assigner 52.

The process flow includes a process order, a name of an apparatus foruse in the process, and a recipe number corresponding to processconditions of a process to be performed in the apparatus and is givenper distribution cassette according to mask blanks to be manufactured.On the production line, the substrate can be identified by the positionin the processes, the cassette number, and the slot number.

The assigner 52 writes the cassette number in an ID tag of thedistribution cassette and, by the use of a data transmission/receptionsection 522, transmits the cassette number, the slot numbers, and theprocess flow to the host computer 51. Referring to FIG. 25, afterreception at a data transmission/reception section 511 of the datatransmitted from the assigner 52, the host computer 51 stores thecassette number, the slot numbers, and the process flow in a processflow storage section 512 while correlating them with each other.

When the distribution cassette finished with the input of the cassettenumber by the assigner 52 (hereinafter, this distribution cassette willbe referred to as the cassette A) is set in a loader port 531 of thefirst film forming apparatus 53, the first film forming apparatus 53reads the cassette number from the ID tag of the cassette A and notifiesit to the host computer 51 by the use of a data transmission/receptionsection 532.

Referring to FIG. 26, the host computer 51, in response thereto,transmits the cassette number of the cassette A, the slot numbers, andthe recipe number of sputtering film formation to the first film formingapparatus 53. With respect to the recipe number, its transmission may beimmediately before the start of operation of the sputtering filmformation.

In the first film forming apparatus 53 in receipt thereof, a recipenumber-sputtering condition collation section 533 identifies asputtering condition corresponding to the recipe number and stores theidentified sputtering condition in a sputtering condition storagesection 534. According to this sputtering condition, a sputteringcondition control section 535 controls a sputtering apparatus 536 tocarry out the sputtering film formation.

The sputtering apparatus 536 takes the substrate from the cassette A andstarts the sputtering film formation. During the sputtering filmformation, the sputtering results are collected and correlated with theslot number.

The substrate finished with the sputtering film formation enters a slotof another distribution cassette (hereinafter referred to as thecassette B) prepared in advance in an unloader port 538. In this event,a slot number, sputtering result, unloader slot number collectionsection 537 (hereinafter referred to as the collection section 537)collects the slot number in the cassette A, the correlated sputteringresults, and a slot number in the cassette B and transmits them to thehost computer 51 by the use of the data transmission/reception section532. When slots of the cassette B are all occupied by the substrateshaving been subjected to the first film formation, the collectionsection 537 notifies the host computer 51 to that effect as well as of acassette number of the cassette B.

In response thereto, the host computer 51 specifies the next process interms of the cassette number B, the cassette number A, and the processflow and notifies a transfer destination to a non-illustrated cassettetransfer portion. Further, the host computer 51 transmits the cassettenumber of the cassette B and the recipe number of sputtering transmittedto the first film forming apparatus 53, to the first film defectinspection apparatus 54.

Referring to FIG. 27, in response to receipt of them at a datatransmission/reception section 541, the first film defect inspectionapparatus 54 gives them to a cassette number-recipe number collationsection 542.

When the distribution cassette is carried into a loader port 543, thecassette number-recipe number collation section 542 identifies a recipenumber corresponding to the cassette number read from an ID tag of thedistribution cassette. Herein, if the cassette number is that of thecassette B, there is obtained the recipe number that was used when thesputtering film formation was applied to the substrates placed in thecassette B.

In a defect inspection condition storage section 544, there is stored inadvance a correlation between recipe numbers and inspection conditionsto be carried out for films formed under recipe conditions indicated bythe recipe numbers. In response to receipt of the recipe number from thecassette number-recipe number collation section 542, the defectinspection condition storage section 544 outputs the inspectioncondition to be carried out.

According to this inspection condition, a defect inspection conditioncontrol section 545 controls a defect inspection apparatus 546 to carryout an inspection. The defect inspection apparatus 546 outputs aninspection result as defect inspection information. The inspectedsubstrate is placed in a slot of another distribution cassette(hereinafter referred to as the cassette C) set in advance in anunloader port 547.

An unloader cassette number, unloader slot number assigning portion 548assigns a cassette number to the cassette C and, by the use of the datatransmission/reception section 541, transmits the cassette number of thecassette C, slot numbers of the cassette C, and the defect inspectioninformation of the substrates placed in the slots to the host computer51 while correlating them with each other.

The host computer 51 stores the transmitted information in aninformation storage section 513 while correlating it with the sputteringresults and so on obtained in the first film forming apparatus 53.

With respect to the second film forming apparatus 55 and the second filminspection apparatus 56, explanation thereof is omitted because, ascompared with the first film forming apparatus 53 and the first filminspection apparatus 54, respectively, there is a difference only due todifference in kind of a film to be formed, but no large difference incomponents and operation. This also applies to the resist film formingapparatus 57 and the resist film defect inspection apparatus 58 shown inFIG. 28.

Based on the information collected from the first film forming apparatus53, the first film inspection apparatus 54, the second film formingapparatus 55, the second film inspection apparatus 56, the resist filmforming apparatus 57, and the resist film inspection apparatus 58 asdescribed above, a defect information collation section 514 produces thefirst-film film information, the second-film film information, and theresist-film film information described in the first embodiment andcollates them with each other to produce the mask blank informationshown in FIG. 17.

In the foregoing embodiments, when setting the substrate or the maskblank in the distribution cassette or the receiving case, on thesubstrate holder of the sputtering apparatus, or on the stage of thedefect inspection apparatus, the substrate is managed to be aligned inthe specific directivity (direction) on the basis of the notch mark orthe film mark 3 or 6. However, not limited thereto, the directivity ofthe substrate can be specified only by the notch mark 1 in all the maskblank manufacturing processes and hence the directivity of the substratemay be managed only the notch mark 1.

Instead of the notch mark 1 or the film mark 3 or 6, use may be made ofa reference mark given to the substrate. In this case, the referencemark may have a shape that can specify the directivity (direction) ofthe substrate.

The layout position of the reference mark on the substrate or the maskblank may be a position that is rotation asymmetric with respect to thecenter of the substrate.

In the foregoing embodiments, the film information is film informationof the plurality of films formed on the substrate. However, the filminformation to be acquired may be that of the single film. This isapplicable even to the information acquired when the mask blank isshipped from the mask blank factory. Even in this case, there is thefunction of ensuring the consistency between the reference point and theXY coordinate system of the film information and the reference point andthe XY coordinate system of the mask blank. Information of the surfaceof the substrate may be included other than the film information.

In the foregoing embodiments, the mask fabrication supporting method ofthis invention has been described by citing, as an example of the maskblank, the halftone phase shift mask blank having the MoSiN halftonefilm, the Cr light shielding film, and the resist film formed on theglass substrate. However, not limited thereto, it is also applicable toa so-called photomask blank having a Cr light shielding film and aresist film formed on a glass substrate or a reflective mask blankhaving a multilayer reflective film, an absorbent film, and a resistfilm formed on a glass substrate.

Further, in the foregoing mask blank, this invention can be utilizedeven in the case where the resist film is not formed.

Further, this invention is not limited to the film material of thehalftone film or the film material of the light shielding film describedin the embodiments and use may be made of other film materials that aregenerally applicable to mask blanks.

In the foregoing embodiments, the ID tag is provided per distributioncase. However, although the distribution case is not the case, the IDtag may be used by reattaching it to a distribution case for use in thenext process.

While this invention has been described in terms of the embodiments,this invention is not limited thereto and changes and improvementsthereof are of course possible within the general knowledge of a personskilled in the art.

For example, in the foregoing embodiments, the film information includesX and Y coordinates of the XY coordinate system determined in advance onthe film on the basis of the predetermined direction of the substrate,the size of each defect, and the type of each defect. However, the kindsof measurement values and the number thereof at the respectivecoordinates are not limited thereto. It is considered that valuesrelating to the shape such as flatness, electrical property values suchas electrical resistance value, optical property values such asrefractive index, and so on are included as film information. Amongthese measurement values, all or part of them may be included in thefilm information.

In the substrate information and various film information, theorthogonal coordinate system is used as a coordinate system. However,not limited thereto, it may be a polar coordinate system instead or athree-dimensional coordinate system may be used instead of thetwo-dimensional coordinate system. For example, assuming that the XYZcoordinate system is used for film information, it is possible toinclude such information that a hole is present at a position of depth Zat a point given by X and Y on the surface of a film, and hence, itbecomes possible to acquire more detailed mask blank information.

1. A mask blank information acquisition method for acquiring mask blankinformation being information relating to a mask blank having aplurality of films stacked on a surface of a substrate, wherein: saidmask blank information comprises substrate information and one or morefilm information or two or more film information; said substrateinformation comprises position information in a plane coordinate systemcorresponding to the surface of the substrate and state informationindicating a state of the substrate correlated with the positioninformation; said film information each comprises position informationin a plane coordinate system corresponding to the corresponding one ofthe films and state information indicating a state of said filmcorrelated with the position information; and said plane coordinatesystems of said substrate information and said film informationcomprised in said mask blank information have predetermined correlationwith each other.
 2. The method claimed in claim 1, comprising the stepsof: forming a first film on the surface of the substrate or on anotherfilm formed on the surface of the substrate; acquiring first filminformation relating to a state of said first film; forming a secondfilm on said first film; acquiring second film information relating tosaid second film; and producing mask blank information comprising saidfirst film information and said second film information.
 3. The methodclaimed in claim 1, comprising the steps of: preparing the substrate;acquiring substrate information relating to a state of said substrate;forming a film on the surface of said substrate; acquiring filminformation relating to a state of said film; and producing mask blankinformation comprising said substrate information and said filminformation.
 4. The method claimed in claim 1, wherein a reference pointof said plane coordinate system has predetermined correlation.
 5. Themethod claimed in claim 1, wherein a reference point of said planecoordinate system is determined on the basis of at least one of a markformed at the substrate and a mark formed at the film.
 6. The methodclaimed in claim 1, comprising a step of collating said substrateinformation and/or said film information with each other.
 7. The methodclaimed in claim 1, wherein said state information comprises at leastone of surface form information and optical property information.
 8. Themethod claimed in claim 1, wherein at least one of said films is a phaseshift film adapted to shift a phase of exposure light.
 9. The methodaccording to claim 1, wherein said mask blank information comprisesinformation produced by projecting said substrate information and saidfilm information of one or more of the films onto a plane or informationproduced by projecting said film information of the plurality of filmsonto a plane.
 10. The method claimed in claim 1, comprising a step ofproviding a detectable reference mark as state information at apredetermined position of the substrate and/or the film before acquiringsaid film information, wherein said mask blank information comprisesinformation indicating a direction of the substrate or the mask blankdetermined on the basis of said reference mark.
 11. The method claimedin claim 10, wherein the reference mark is produced in a shapeapplicable to specify a direction.
 12. The method claimed in claim 10,wherein: a profile of the substrate has a shape having rotationsymmetry; and a shape of the substrate comprising the reference markprovided has rotation asymmetry.
 13. The method claimed in claim 10,comprising the steps of: forming a film a on the substrate by anapparatus A and measuring said film a to acquire film information acomprising said reference mark; removing said substrate from saidapparatus A; placing said substrate in a case while aligning saidsubstrate in a predetermined direction on the basis of said referencemark; transferring said case to another apparatus B; setting saidsubstrate in said apparatus B while aligning said substrate in apredetermined direction on the basis of said reference mark, and forminga film b on said substrate by said apparatus B and measuring said film bto acquire film information b comprising said reference mark.
 14. Themethod claimed in claim 10, comprising the steps of: setting thesubstrate in a measuring apparatus to measure the substrate, therebyacquiring said substrate information comprising said reference mark;removing said substrate from said measuring apparatus; placing saidsubstrate in a case while aligning said substrate in a predetermineddirection on the basis of said reference mark; transferring said case toan apparatus A; setting said substrate in said apparatus A whilealigning said substrate in a predetermined direction on the basis ofsaid reference mark; and forming a film a on said substrate by saidapparatus A and measuring said film a to acquire film information acomprising said reference mark.
 15. The method claimed in claim 1,wherein the acquired mask blank information is referred to foridentifying the mask blank individual.
 16. The method claimed in claim1, wherein said state information comprises at least two kinds ofmeasurement values.
 17. The method claimed in claim 1, wherein at leastone of said substrate information and said film information comprisesposition information in a three-dimensional coordinate system furthercomprising coordinates in a thickness direction of the substrate or thefilm.
 18. A mask blank information providing method for providing maskblank information relating to a mask blank fabricated by stacking aplurality of films on a substrate, providing the mask blank informationacquired by the mask blank information acquisition method claimed inclaim 1, along with said mask blank.
 19. A transfer mask fabricationsupporting method for supporting fabrication of a transfer mask byproviding mask blank information to a mask maker, said method comprisingthe step of providing the mask blank information to the mask maker bythe mask blank information providing method claimed in claim 18,wherein, in order to prevent fabrication of a defective transfer mask,the mask blank information provided is referred to for specifying aregion on the corresponding mask blank where a mask pattern is to beformed, before forming the mask pattern on the mask blank.
 20. Atransfer mask fabrication supporting method for supporting fabricationof a transfer mask by providing mask blank information to a mask maker,said method comprising the step of providing the mask blank informationto the mask maker by the mask blank information providing method claimedin claim 18, wherein a reference point of a coordinate system in themask blank information is notified to the mask maker through saidreference mark, and said mask maker provided with the mask blankinformation acquires said correlation between said plane coordinatesystems through said reference mark and determines a region, where amask pattern is to be formed, based on said acquired correlation andsaid mask blank information.
 21. A transfer mask fabrication supportingmethod claimed in claim 19, wherein the mask pattern formed on the maskblank comprises a relatively dense pattern block and a relatively sparsepattern block.
 22. A transfer mask manufacturing method formanufacturing a transfer mask by forming a mask pattern, which is to bea transfer pattern, on a mask blank, determining a region where the maskpattern is to be arranged on the mask blank, based on the mask blankinformation acquired by the mask blank information acquisition methodclaimed in claim
 1. 23. A mask blank manufacturing method formanufacturing a mask blank, comprising the mask blank informationacquisition method claimed in claim
 1. 24. A mask blank informationacquisition system for acquiring mask blank information beinginformation relating to a mask blank having a plurality of films stackedon a surface of a substrate, comprising: at least two informationacquisition means among; means for acquiring substrate informationrelating to a state of the substrate; means for acquiring first filminformation relating to a state of a first film formed on the surface ofthe substrate or on another film formed on the surface of the substrate;means for acquiring second film information relating to a state of asecond film being a film other than said first film formed on thesurface of said substrate, and means for producing mask blankinformation comprising the information acquired by said informationacquisition means.
 25. The system claimed in claim 24, wherein: saidsubstrate information comprises position information in a planecoordinate system corresponding to the surface of the substrate andstate information indicating a state of the substrate correlated withthe position information; said film information comprises positioninformation in a plane coordinate system corresponding to the film andstate information indicating a state of said film correlated with theposition information; and said coordinate systems of said substrateinformation and said film information in said mask blank informationhave predetermined correlation.
 26. The method claimed in claim 10,wherein said substrate has a polygonal shape, and said reference mark isprovided in a region sandwiched between mutually contacting two sides ofsaid substrate.
 27. The method claimed in claim 10, wherein the evennumber of reference marks are provided at mutually rotation asymmetricpositions.
 28. A transfer mask fabrication supporting method forsupporting fabrication of a transfer mask by providing mask blankinformation to a mask maker, said method comprising a step of providingmask blank information of a plurality of mask blanks to the mask makerby the mask blank information providing method claimed in claim 18,wherein the mask blank information provided is referred to for selectingone of said plurality of mask blanks before forming a mask pattern. 29.The method claimed in claim 13, further comprising, after the step ofacquiring said film information b, a step of placing said substrate in acase while aligning said substrate in a predetermined direction on thebasis of said reference mark.
 30. The method claimed in claim 14,comprising, after the step of acquiring said film information a, a stepof placing said substrate in a case while aligning said substrate in apredetermined direction on the basis of said reference mark.
 31. A maskblank providing method for providing a mask blank, providing, along witha mask blank, mask blank information relating to said mask blankacquired by the mask blank information acquisition method claimed inclaim 1.